Add bin/coverallsFromFiles.js that takes filenames as arguments

[freshvolk]

Previously the way to send your lcov.info files to Coveralls was by piping to bin/converalls.js

This adds a script that can be called with lcov files as arguments, then performs the coveralls.js actions on each file.

[nickmerwin]

Hi @freshvolk could you please add some tests for this?

Thank you!

[sindresorhus]

I think the main coveralls binary should just support both stdin and file argument:

$ cat lcov.info | coveralls
$ coveralls lcov.info