Allow date to be passed in as string. Issue #3
Removed unnecessary checks when string is passed in. Issue #3
Added test for passing in string.

Fixes #3
Adds support for timestamps.

Fixes #5 #3
Better test for timestamp.

Fixes #5
Merge branch 'master' into feature/5-pass-in-timestamp

* master:
  Added noConflict method and test.

Conflicts:
	.gitignore
	lib/relative.js
	test/relative.test.js
Merge pull request #9 from firstandthird/feature/5-pass-in-timestamp

Feature/5 pass in timestamp