Co-authored-by: gavin <gavin18d@gmail.com>

Why?
- Coveralls had login issues and we were not able to view files to find the actual uncovered lines
- Codecov has better reporting (status checks & commit diff coverage, ), UX (better folder/file navigation, faster page loads), and has more features.
- Codecov will not require additional step of
coverage wrap-up for parallel builds (it manages it internally somehow).

- Decoupled coverage code from testing to setup code coverage before any import happen to get accurate coverage (before it used to skip import statements for some files)

* Maintain common settings for coverage settings of parallel and base test suites
* Expand FRAPPE_EXCLUSIONS list based on coveralls.io report