Reverted Travis config.

Will add Travis config to pyota-ccurl repo for its own testing.

Author: todofixthis

.travis.yml

@@ -3,10 +3,5 @@ python:
   - "2.7"
   - "3.5"
   - "3.6"
-env:
-  - USE_CCURL=0
-  - USE_CCURL=1
-install:
-  - "pip install -e ."
-  - "if [[ $USE_CCURL=1 ]] then; pip install --pre pyota-ccurl; fi"
+install: "pip install ."
 script: "nosetests"