add GetDiff Handler
URL for GetDiff Handler
add GetDiff Handler
fixed merge problem
Merge branch 'master' of github.com:joaopaulovieira/gandalf

Conflicts:
	api/handler.go
	api/handler_test.go
	webserver/main.go
fix URL GetDiff
Merge pull request #137 from joaopaulovieira/master

Create GetDiff Handler and unit tests for him