Added classes and empty spec
Removed unnecessary methods
Added 'time' and 'day' spec
Added readme stub
Fixed typo in readme
Added 'month' and spec
Added 'year' and spec
Refecatored 'time', 'day', 'month', 'year' spec
Added spec for 'week', but not all
Finished with 'week' spec
Added date creation and spec
Added date compare and spec
Added common header
Moved NSDate categories source code from 'Classes' to 'Categories'
folder
Added travis-CI configuration file