test: Initial commit for tests

[anishkny]

Includes:

• mocha, nyc (coverge)
• Mochaawesome reports uploaded to artifacts. e.g. report
• Coverage uploaded to Coveralls - you would need to setup COVERALLS_REPO_TOKEN env var in CircleCI
• Test stub (doesn't actually test yet)

Fixes #16

[vot]

Hey @anishkny,

This is great - thanks for adding scaffolding for tests.
Never used nyc so curious about differences between this and istanbul.

Merging now

[anishkny]

I believe they rebranded istanbul to nyc. Its basically the same thing.

[vot]

Hah that'd explain it - I remember seeing it in a few places but never looked into it :)

Once again many thanks for sorting this out. I've already set up Coveralls integration and updated the badge in readme.
Everything works exactly as expected 👍