bump travis python version

.travis.yml

@@ -70,7 +70,7 @@ install:
     fi
 - >
     if [[ "$PYTHON" == true ]]; then
-      pyenv local 3.6
+      pyenv local 3.7
       pip3 install --user mkdocs rgain3
       pushd python_apps/airtime_analyzer
       python3 setup.py install --dry-run --no-init-script

travis/python.sh

@@ -4,10 +4,8 @@ set -xe
 
 [[ "$PYTHON" == false ]] && exit 0
 
-python3 --version
-
 pushd python_apps/airtime_analyzer
-pyenv local 3.6
+pyenv local 3.7
 pip3 install -e .
 nosetests
 popd