removing testing for 3.5 on travis CI

Author: jankoslavic

.travis.yml

@@ -1,8 +1,9 @@
 language: python
 python:
 # - "2.7"
- - "3.5"
+# - "3.5"
  - "3.6"
+ - "3.7" 
 # command to install dependencies
 install: "pip install -r requirements.txt"
 # command to run tests