Add CI/CD workflows with tox and GitHub Actions for comprehensive tes…

…ting, styling, and quality checks (#16)

## Summary
Implements a series of GitHub Actions workflows and tox environments to
streamline the CI/CD processes for the project. It replaces the previous
Makefile-based pathways and focuses on modernizing the development,
testing, and deployment practices.

## Details
- CI/CD Workflows: Introduced multiple GitHub Actions workflows for
development, nightly builds, quality checks, and releases.
- Development Workflow: Runs on pull requests to any branch. Includes
unit tests and integration tests for Python versions 3.8 to 3.12.
- Nightly Workflow: Scheduled to run nightly, ensuring continuous
integration health with the unit, integration, and end-to-end tests.
- Quality Workflow: This runs on pushes to the main branch and pull
requests. It ensures code quality with linting, formatting, and type
checking.
- Release Workflow: Triggers on push to release branches, running
comprehensive tests to prepare for new releases.
- tox Configuration: Updated tox.ini to define environments for unit
tests, integration tests, end-to-end tests, quality checks, style
checks, type checks, build, and clean operations.
- Developer Documentation: Expanded DEVELOPING.md to guide contributors
in setting up the development environment, running tests, and
maintaining code quality.
- README Updates: Updated project documentation to reflect the new CI/CD
practices and removed outdated Makefile instructions.

## Test Plan
Pending running the new GitHub Actions workflows. If any issues pop up,
those will be fixed either in this diff or in subsequent ones.

.github/workflows/development.yml

@@ -0,0 +1,43 @@
+name: Development
+
+on:
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run unit tests
+        run: tox -e test-unit -- -m "smoke or sanity"
+
+  integration-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run integration tests
+        run: tox -e test-integration -- -m smoke

.github/workflows/nightly.yml

@@ -0,0 +1,69 @@
+name: Nightly
+
+on:
+  schedule:
+    - cron: '0 0 * * *'  # Runs at midnight every night
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run unit tests
+        run: tox -e test-unit -- --cov-report=term-missing --cov --cov-fail-under=75
+
+  integration-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run integration tests
+        run: tox -e test-integration -- -m "smoke or sanity"
+
+  e2e-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run e2e tests
+        run: tox -e test-e2e -- -m smoke

.github/workflows/quality.yml

@@ -0,0 +1,46 @@
+name: Quality
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  quality-check:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run quality checks
+        run: tox -e quality
+
+  type-check:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run type checks
+        run: tox -e types

.github/workflows/release.yml

@@ -0,0 +1,70 @@
+name: Release
+
+on:
+  push:
+    branches:
+      - release/**
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run unit tests
+        run: tox -e test-unit -- --cov-report=term-missing --cov --cov-fail-under=75
+
+  integration-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run integration tests
+        run: tox -e test-integration -- --cov-report=term-missing --cov --cov-fail-under=75
+
+  e2e-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python:
+          - "3.12"
+          - "3.11"
+          - "3.10"
+          - "3.9"
+          - "3.8"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python }}
+      - name: Install dependencies
+        run: pip install tox
+      - name: Run e2e tests
+        run: tox -e test-e2e -- --cov-report=term-missing --cov --cov-fail-under=75