Moved types used by tests to CommonTestTypes, unifing them

[przemoli]

#129
I moved types from test/Data/Swagger/{ParamSchemaSepc|SchemaSpec} to single module, and for duplicates I just copied extra Deriving and instances.

[fizruk]

The problem with GHC 7.8 is that you have to import Control.Applicative to get pure and <$>.
Something like this should work:

#if __GLASGOW_HASKELL__ <710
import Control.Applicative
#endif

[fizruk]

Also, apparently you have all the code indented by 2 whitespaces, that's probably unintended?

Apart from those comments seems good, thanks for your contribution!

[phadej]

-#if __GLASGOW_HASKELL__ <710
-import Control.Applicative
-#endif
+import Prelude ()
+import Prelude.Compat

[przemoli]

I've updated imports to use Prelude.Compat, and I've rebased my commits on top of recent PR.

Edit: I still haven't fixed indentation. What should it be?
Edit2: Ok. Whole module was intended 2 whitespaces. Fixed.