Run tests in python 3.6 by default

This allows us to do a proper `bones-check` with `black`.
The hardware tests are still in 3.5.2 to support NxSDK.

.nengobones.yml

@@ -441,7 +441,7 @@ docs_conf_py:
     - import nengo
 
 travis_yml:
-  python: 3.5.2
+  python: 3.6
   global_vars:
     NENGO_VERSION: nengo[tests]
     NENGO_DL_VERSION: nengo-dl
@@ -458,6 +458,7 @@ travis_yml:
         NENGO_VERSION: git+https://github.com/nengo/nengo.git#egg=nengo[tests]
         NENGO_DL_VERSION: git+https://github.com/nengo/nengo-dl.git#egg=nengo-dl
     - script: hardware
+      python: 3.5.2  # nxsdk requires 3.5.2
       env:
         NENGO_VERSION: git+https://github.com/nengo/nengo.git#egg=nengo[tests]
         NENGO_DL_VERSION: git+https://github.com/nengo/nengo-dl.git#egg=nengo-dl
@@ -478,7 +479,7 @@ ci_scripts:
       - $NENGO_VERSION
       - $NENGO_DL_VERSION
       - jupyter
-      - numpy
+      - numpy>=1.14  # avoid the default-installed 1.13 on TravisCI
     coverage: true
     nengo_tests: true
   - template: static

.travis.yml

@@ -1,7 +1,7 @@
 # Automatically generated by nengo-bones, do not edit this file directly
 
 language: python
-python: 3.5.2
+python: 3.6
 notifications:
   email:
     on_success: change
@@ -43,6 +43,7 @@ jobs:
       NENGO_DL_VERSION="git+https://github.com/nengo/nengo-dl.git#egg=nengo-dl"
       NXSDK_VERSION="0.8.5"
       SCRIPT="hardware"
+    python: 3.5.2
   -
     env:
       NENGO_VERSION="git+https://github.com/nengo/nengo.git#egg=nengo[tests]"