update travis config to avoid test timeout

.travis.yml

@@ -10,6 +10,6 @@ install:
   - "pip install -r requirements.txt"
   - "pip install coveralls"
 # command to run tests
-script: cd tests/Exscript/; coverage run --source=Exscript ./run_suite.py 1
+script: cd tests/Exscript/; travis_wait coverage run --source=Exscript ./run_suite.py
 after_success:
   coveralls