Fix: CircleCI check should fail if unit tests fail

[willvedd]

🔧 Changes

Currently, our unit test suite is failing but gets marked as a pass in CircleCi. The npm run test:coverage is a composition of two commands, running unit tests and generating test coverage. These two commands are joined by a semicolon (;) which means that the exit code of the first command is essentially ignored in favor of the test coverage command, which rarely exits with a non-zero code. Instead, these commands should be joined with && to signal an error if either two of the commands returns a non-zero exit code. Example of tests failing in CI but passing the stage.

📚 References

Example

🔬 Testing

Running npm run test:coverage followed by echo $? to verify the exit code of the resulting change.

📝 Checklist

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)

[willvedd]

Because the current master branch has a couple of failing tests, this PR should now fail the CircleCI unit test stage. It should pass once the corrections of unit tests are fixed with #708 .