🔥 remove python verions lower than 3.6

Author: chfw

.travis.yml

@@ -13,24 +13,10 @@ env:
   - DJANGO_VERSION=2.0.8
   - DJANGO_VERSION=2.1
 python:
-  - 2.7
-  - 3.5
   - 3.6
   - 3.7
 matrix:
   exclude:
-    - python: 2.7
-      env: DJANGO_VERSION=2.0.8
-    - python: 2.7
-      env: DJANGO_VERSION=2.1
-    - python: 3.5
-      env: DJANGO_VERSION=1.6.11
-    - python: 3.5
-      env: DJANGO_VERSION=1.7.11
-    - python: 3.5
-      env: DJANGO_VERSION=1.8.18
-    - python: 3.5
-      env: DJANGO_VERSION=1.11.9
     - python: 3.6
       env: DJANGO_VERSION=1.6.11
     - python: 3.6