fix(timepickerSpec): fix testing error on different timezones/languages

When executing the `timepickerSpec` tests, a test failed while matching a RegEx saying:
```
PhantomJS 1.9.2 (Windows 8) timepicker should correctly update both input value
and bound model for date type FAILED
        Expected Date(Tue Oct 01 2013 01:00:04 GMT+0200 (ora legale Europa occid
entale)) to match /(Mon|Tue|Wed|Thu|Fri|Sat|Sun) (Jan|Feb|Mar|Apr|May|Jun|Jul|Au
g|Sep|Oct|Nov|Dec) \d{1,2} \d{4} 01:00:\d{2} GMT[-+]\d{4} \([A-Z]{3,4}\)/.
```
The latest part of the string (`ora legale Europa occidentale`) didn't match the `[A-Z]{3,4}` RegEx part, so it had to be changed for the tests to succeed (please see http://gskinner.com/RegExr/?36i47 for a RegEx test).
Also, after calling `grunt test`, `grunt` complained about `source-map` missing, so it was added to the `devDependencies`.