Add follow option

[JoshHeng]

What's Changing

Add follow option to add the --follow parameter when executing git log

Change Type

Indicate the type of change your pull request is:

• patch
• minor
• major

[JoshHeng]

Hey! I'm working on a project which uses gitlog and have added an option to add the --follow parameter to be passed into the command line. This means that it will correctly track previous contributors to the a file, even if it has been renamed.

If this could be reviewed/merged and then a new package built on npm that would be great. Thank you!

[domharrington]

Hey! Thank you for your contribution! I've just approved the tests to run, so if they pass then i'll get this merged and released for you. Thanks.

[domharrington]

Published to npm as v5.1.0: https://www.npmjs.com/package/gitlog/v/5.1.0

Thanks again!

[JoshHeng]

Thank you!