Merge pull request #1710 from jdufresne/py36

Enable Travis CI testing for Python 3.6

.travis.yml

@@ -20,6 +20,9 @@ script:
   - echo -e "\n\n>>> Building python35 plugin"
   - /usr/bin/python3.5 -V
   - /usr/bin/python3.5 uwsgiconfig.py --plugin plugins/python base python35
+  - echo -e "\n\n>>> Building python36 plugin"
+  - /usr/bin/python3.6 -V
+  - /usr/bin/python3.6 uwsgiconfig.py --plugin plugins/python base python36
   - echo -e "\n\n>>> Building rack plugin"
   - rvm use 2.4
   - ruby -v
@@ -35,7 +38,7 @@ before_install:
   - sudo add-apt-repository ppa:deadsnakes/ppa -y
   - sudo add-apt-repository ppa:ondrej/php -y
   - sudo apt-get update -qq
-  - sudo apt-get install -qqyf python2.6-dev python3.4-dev python3.5-dev
+  - sudo apt-get install -qqyf python2.6-dev python3.4-dev python3.5-dev python3.6-dev
   - sudo apt-get install -qqyf libxml2-dev libpcre3-dev libcap2-dev
   - sudo apt-get install -qqyf php7.2-dev libphp7.2-embed libargon2-0-dev libsodium-dev
   - sudo apt-get install -qqyf liblua5.1-0-dev