Default CI testing is to skip slow tests

Author: pwolfram

.travis.yml

@@ -76,7 +76,7 @@ install:
   - python setup.py install
 
 script:
-  - py.test xarray --cov=xarray --cov-report term-missing --verbose
+  - py.test xarray --cov=xarray --cov-report term-missing --verbose --skip-slow
 
 after_success:
   - coveralls

appveyor.yml

@@ -38,4 +38,4 @@ install:
 build: false
 
 test_script:
-  - "py.test xarray --verbose"
+  - "py.test xarray --verbose --skip-slow"