refactor registry to include OS version filtering on the package index (#64)

* refactor registry to include OS version filtering on the package index

* remove commented code, clean up tests

* removed unused types

* remove disabled test

* remove unused type

* fix query parsing

* remove unused code

* more purging

* MOAR PURGING

* normalize data model, fix all type errors

* rename get parameter

src/Handler/Version.hs

@@ -19,14 +19,10 @@ import           Lib.Error                      ( S9Error(NotFoundE) )
 import           Lib.PkgRepository              ( getBestVersion )
 import           Lib.Types.AppIndex             ( PkgId )
 import           Network.HTTP.Types.Status      ( status404 )
-import           Settings
 import           Util.Shared                    ( getVersionSpecFromQuery
                                                 , orThrow
                                                 )
 
-getVersionR :: Handler AppVersionRes
-getVersionR = AppVersionRes . registryVersion . appSettings <$> getYesod
-
 getPkgVersionR :: PkgId -> Handler AppVersionRes
 getPkgVersionR pkg = do
     spec <- getVersionSpecFromQuery