Updated travis configuration for proper GHC 7.10 support

Author: ameingast

.travis.yml

@@ -1,12 +1,34 @@
-language: haskell
-
-ghc: 
-    - 7.6
-    - 7.8
-    - 7.10
+sudo: required
 
 services:
-    - postgresql
+ - postgresql
 
 before_script:
-    - psql -c 'create database test;' -U postgres
+ - psql -c 'create database test;' -U postgres
+
+env:
+ - CABALVER=1.18 GHCVER=7.6.3
+ - CABALVER=1.18 GHCVER=7.8.4
+ - CABALVER=1.22 GHCVER=7.10.2
+
+before_install:
+ - travis_retry sudo add-apt-repository -y ppa:hvr/ghc
+ - travis_retry sudo apt-get update
+ - travis_retry sudo apt-get install cabal-install-$CABALVER ghc-$GHCVER
+ - export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
+
+install:
+ - cabal --version
+ - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
+ - travis_retry cabal update
+ - cabal install --only-dependencies --enable-tests --enable-benchmarks
+
+script:
+ - cabal configure --enable-tests --enable-benchmarks -v2
+ - cabal build
+ - cabal test
+ - cabal check
+ - cabal sdist
+
+- SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
+  (cd dist && cabal install --force-reinstalls "$SRC_TGZ")