Switch to unittest

Have to install it first

Remove Azure steps for attempt at pytest

azure-pipelines.yml

@@ -56,20 +56,14 @@ jobs:
     - script: sh -c 'cd micropython/mpy-cross && make'
       displayName: Make mpy-cross
 
-    - script: sh -c 'cd micropython/ports/unix && make axtls MICROPY_HEAP_SIZE=20971520 && make MICROPY_HEAP_SIZE=20971520'
-      displayName: Make MicroPython (20MB heap)
+    - script: sh -c 'cd micropython/ports/unix && make axtls && make'
+      displayName: Make MicroPython
 
-    - script: curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
-      displayName: Retrieve get-pip.py
+    - script: micropython/ports/unix/micropython -c 'import upip; upip.install(["unittest"])'
+      displayName: Install tooling
 
-    - script: micropython/ports/unix/micropython get-pip.py
-      displayName: Install pip
-
-    - script: micropython/ports/unix/micropython -m pip install pytest
-      displayName: Install dependencies
-
-    - script: micropython/ports/unix/micropython -m pytest
-      displayName: Run tests
+    - script: micropython/ports/unix/micropython -X heapsize=50M -m unittest
+      displayName: Run unittest
 
 - job: flake8
   pool: