Add exit code tests

[joshbax189]

Before changing the behavior of errors as discussed in #273 , I wanted to add more tests that check the current behavior.

This PR adds tests which check, for each command:

• bad input exits with error
• input with warnings exits with error when --strict is set
• multiple inputs (i.e. commands which apply to multiple files or have multiple steps) should execute as far as possible
  when --allow-error is set, then exit with error

I'll add some script helpers that check error statuses and note any discrepancies I see.
I'll comment out and mark any currently failing expectations with #FIXME so that the CI run is clean.

[joshbax189]

Right now, this only has checks for the analyze command, but I wanted to get feedback on the usage of the helper functions in test. Sorry if it triggers a lot of CI failures!

[jcs090218]

I like the idea! These are my thoughts on the test implementation. :D

• Open a new workflows/streams.yml and test it under the test/streams/ folder instead of testing for each command. Since most commands are implemented similarly (Node.js forward Emacs' streams), testing for each command could be more manageable.
• From the point above, move all test-related files under test/streams/ (testing.sh, Eask-normal, Eask-warn, etc.)

WDYT? :)

[joshbax189]

I think I chose the worst possible example command 💥 I want to test more than just Eask file errors and warnings, which I might have implied by this choice...

A better example might be eask compile. I want a normal .el file, an .el file that compiles with a warning and one that errors. I want to specifically test the "recover after error" behavior of the compile command itself, not just the warnings from the Eask file. E.g. test that eask compile --allow-error error.el normal.el should exit with non-zero status, but also compile normal.elc. (It does, by the way).

I'll add a few more examples in a new subfolder of test, like you suggested, then check in again later.

[jcs090218]

No worries! I'm more keen to test this feature explicitly, so it's easier to track and test in one place. 🤔