Bugfix haskell-stack test.

test/tests/haskell-stack/container.sh

@@ -2,7 +2,6 @@
 set -e
 
 # stack mostly sends to stderr
-stack new myproject 2> /dev/null
+stack --resolver ghc-$(ghc --print-project-version) new myproject 2> /dev/null
 cd myproject
-stack config set resolver ghc-$(ghc --print-project-version) 2> /dev/null
-stack build 2> /dev/null
+stack run 2> /dev/null