Added OCMock 2.1.1 podspec.

OCMock does not use commit tags.  The pod spec lint WARN error can be ignored.


 -> OCMock (2.1.1)
    - WARN  | Git sources should specify a tag.
    - NOTE  | [xcodebuild]  OCMock/Source/OCMock/OCMockObject.m:146:24: warning: values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead [-Wformat]
    - NOTE  | [xcodebuild]  OCMock/Source/OCMock/OCObserverMockObject.m:57:24: warning: values of type 'NSUInteger' should not be used as format arguments; add an explicit cast to 'unsigned long' instead [-Wformat]

Analyzed 1 podspec.

[!] The spec did not pass validation.