Rename RSColorPickerTests to RSColorPickerViewTests

This is in preparation of moving delegate tests to separate file.
Add CPTestCase import to precompiled header. Move delegate to separate file.

I added the CPTestCase.h import to the PCH because Xcode doesn't add the import automatically when you create a new testcase subclass with a custom superclass specified. Therefore it doesn't automatically index and add to the test list. This should fix that.