Add assert that we have some kind of blas on travis.

.travis.yml

@@ -65,6 +65,7 @@ script:
   - echo "$PART"
   - cd -; cd Theano
   - python -c 'import theano; print(theano.config)'
+  - python -c 'import theano; assert(theano.config.blas.ldflags != "")'
   - theano-nose -v $PART
   - if [[ $DOC == "1" ]]; then python doc/scripts/docgen.py --nopdf --check; fi
   - if [[ $DOC == "1" ]]; then python doc/scripts/docgen.py --test --check; fi