Flip test run condition

Author: dolio

.travis.yml

@@ -84,7 +84,7 @@ script:
  - if [ -f configure.ac ]; then autoreconf -i; fi
  - cabal configure --enable-tests $TESTS --enable-benchmarks -v2  # -v2 provides useful information for debugging
  - cabal build   # this builds all libraries and executables (including tests/benchmarks)
- - if [ "$TESTS" = '--disable-tests' ]; then cabal test; fi
+ - if [ "$TESTS" != '--disable-tests' ]; then cabal test; fi
 # - cabal check
  - cabal sdist   # tests that a source-distribution can be generated