Test coverage with coveralls more flexible [#34]

[danactive]

Review steps:

• CLI yarn test:ci in Travis CI

[ghost]

Your pull request doesn't follow our guidelines. Please fix the following:

• Pull request description must include verification steps (?)

Click here for details.

Thank you! 🙏

_{This comment was made by GitMagic – Magically enforcing your contribution guidelines.}

[ghost]

Thank you, the title and description now looks good!

[coveralls]

Coverage remained the same at 92.811% when pulling 685c9b1 on add-test-coverage into fcae8ba on master.

[coveralls]

Coverage remained the same at 92.811% when pulling c439e8c on add-test-coverage into fcae8ba on master.

[coveralls]

Coverage remained the same at 92.811% when pulling a294c5c on add-test-coverage into fcae8ba on master.

[coveralls]

Coverage remained the same at 92.811% when pulling 4319f77 on add-test-coverage into fcae8ba on master.