Fix travis builds

.travis.yml

 language: haskell
 
-notifications:
-  email:
-    on_success: never
-    on_failure: change
-
 env:
- - GHCVER=7.4.1
- - GHCVER=7.4.2
- - GHCVER=7.6.3
  - GHCVER=7.8.1
  - GHCVER=7.8.2
  - GHCVER=7.8.3
- - GHCVER=head
 
 before_install:
  - sudo add-apt-repository -y ppa:hvr/ghc
  - sudo apt-get update
  - sudo apt-get install ghc-$GHCVER
  - export PATH=/opt/ghc/$GHCVER/bin:$PATH
-
-install:
-  - case "$GHCVER" in
-     "head") (cd haddock-library/ && cabal install --enable-tests
-              && cd .. && cabal install --only-dependencies --enable-tests) ;;
-     *)
-       (cd haddock-library/ && cabal install --only-dependencies --enable-tests) ;;
-
-    esac
+ - cd haddock-library
+ - cabal install --only-dependencies --enable-tests
+ - cabal install doctest
+ - cabal configure --enable-tests --ghc-options=-Werror && cabal build && cabal test
+ - doctest -isrc -i$(echo vendor/attoparsec-*) -optP-include -optPdist/build/autogen/cabal_macros.h src/Documentation/Haddock/Parser.hs
+ - cabal install
+ - cd ..
 
 script:
-  # Yes, in case of HEAD we do end up building haddock-library twice
-  # but we want to see the test results.
-  - (cd haddock-library/ && cabal configure --enable-tests --ghc-options=-Werror
-     && cabal build && cabal test && cabal install && cabal install doctest
-     && doctest -isrc -ivendor/attoparsec-0.10.4.0 -optP-include -optPdist/build/autogen/cabal_macros.h src/Documentation/Haddock/Parser.hs)
-  - case "$GHCVER" in
-     "head") (cabal configure --enable-tests --ghc-options=-Werror && cabal build && cabal test) ;;
-     *) ;;
-    esac
+ - cabal configure --enable-tests --ghc-options=-Werror && cabal build && cabal test