haskell: aeson-schema missing test suite

For some reason the .tar.gz on hackage is missing most of the files for
the test suite.  I've opened an issue on
it (timjb/aeson-schema#9), but it's not yet
been acted on.  In the meantime, simply disabling the test suite seems
most sensible.

@peti, could you merge this?

pkgs/development/haskell-modules/configuration-common.nix

@@ -276,6 +276,7 @@ self: super: {
   # Disable test suites to fix the build.
   acme-year = dontCheck super.acme-year;                # http://hydra.cryp.to/build/497858/log/raw
   aeson-lens = dontCheck super.aeson-lens;              # http://hydra.cryp.to/build/496769/log/raw
+  aeson-schema = dontCheck super.aeson-schema;          # http://hydra.cryp.to/build/576244/nixlog/2/raw
   apache-md5 = dontCheck super.apache-md5;              # http://hydra.cryp.to/build/498709/nixlog/1/raw
   app-settings = dontCheck super.app-settings;          # http://hydra.cryp.to/build/497327/log/raw
   aws = dontCheck super.aws;                            # needs aws credentials