travis: requires numpy with new print formatting

Author: mdeff

.travis.yml

@@ -16,7 +16,8 @@ addons:
 
 install:
   - pip install -U pip setuptools
-  - pip install -U .[alldeps,test,doc]
+  - pip install 'numpy>=1.14'
+  - pip install .[alldeps,test,doc]
 
 script:
 # - make lint