Don't re-export Distribution as a new module

We want to encourage users to use the ekg-core package instead.

System/Remote/Distribution.hs

@@ -1,13 +0,0 @@
--- | This module defines a type for tracking statistics about a series
--- of events. An event could be handling of a request and the value
--- associated with the event -- the value you'd pass to 'add' -- could
--- be the amount of time spent serving that request. All operations
--- are thread safe.
-module System.Remote.Distribution
-    ( Distribution.Distribution
-    , Distribution.new
-    , Distribution.add
-    , Distribution.addN
-    ) where
-
-import qualified System.Metrics.Distribution as Distribution

System/Remote/Monitoring.hs

@@ -51,8 +51,8 @@ import Data.Time.Clock.POSIX (getPOSIXTime)
 import Prelude hiding (read)
 
 import qualified System.Metrics as Metrics
+import System.Metrics.Distribution (Distribution)
 import System.Remote.Counter (Counter)
-import System.Remote.Distribution (Distribution)
 import System.Remote.Gauge (Gauge)
 import System.Remote.Label (Label)
 import System.Remote.Snap

ekg.cabal

@@ -26,7 +26,6 @@ cabal-version:       >= 1.8
 library
   exposed-modules:
     System.Remote.Counter
-    System.Remote.Distribution
     System.Remote.Gauge
     System.Remote.Label
     System.Remote.Monitoring