Fixes #275 Add Codecov reports

[bhaveshAn]

Fixes #275

Checklist

• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream master branch.
• The unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

• All the functions created/modified in this PR contain relevant docstrings.

Short description of what this resolves:

Added Codecov reports

Changes proposed in this pull request:

• Added codecov.yml
• Modify Travis.

@zamhaq @ms10398 @mariobehling Please review.

[sansyrox]

@bhaveshAn , what I can understand is that is something similar to codacy.Please explain the need.

[bhaveshAn]

@stealthanthrax Please don't suggest changes/ review the PR, if you are not clear about a feature.
Instead simply make the comment.

Need

Codecov is a reporting tool that is intended to process any coverage report format into a format that is standard across Codecov. You may change the configuration of how Codecov processes reports and expresses coverage information.

The Codecov pull request comment is a highly detailed overview of a pull request. It provides details on the coverage changes in the pull request that help with speeding up code review, and ensuring that pull requests are well tested. The comment is customizable to fit your desired needs.

Samples

Checkout the PRs of https://github.com/fossasia/susper.com/pulls and https://github.com/fossasia/open-event-server/pulls for example. Here projects uses coverage changes in the pull request that help with speeding up code review,

[haquezameer]

@ms10398 @gabru-md codecov should be included?

[ms10398]

Whats your thought @zamhaq

[haquezameer]

@ms10398 Yeah, I think we should.

[gabru-md]

@zamhaq I guess that this PR can wait for some time. We do have to split the script.js file into multiple files for better modularity. So till then, this can be put on a hold. Else it will cause problems for new PRs.
Once we are done with splitting the file, then I support that this should be merged.
Rest is your thoughts! and your final take :)

[haquezameer]

ok so you guys are working on that? @gabru-md cool. Thanks 😄

[gabru-md]

Will start working on that too!
Meanwhile can you please see #287 and merge?

[prateekiiest]

Any updates on this?

[haquezameer]

@prateekiiest This was put on hold because of on-going work on #156 and idk about the current status according to gsoc about which are priority issues now.