Remove clearing of sandbox, attempt to fix travis test

frameworks/Haskell/yesod/setup.sh

@@ -5,11 +5,6 @@ export PATH=${HASKELL_HOME}/bin:$PATH
 cd bench
 
 ${CABAL_HOME}/bin/cabal update
-
-# Run cabal sandbox delete in order to clear old, 
-# previously installed dependencies. 
-${CABAL_HOME}/bin/cabal sandbox delete
-
 ${CABAL_HOME}/bin/cabal sandbox init
 ${CABAL_HOME}/bin/cabal --bindir=${TROOT}/bench/dist/build/bench install