Add tox

Switches Travis from three executors to one. The concurrency limits
are still needed in the event that multiple pushes happen while tests
are running, but this makes tests run faster because the container
only needs to be setup once. It also makes running tests locally against
multiple Python versions simpler.

.gitignore

@@ -1,4 +1,5 @@
 .env
+/.tox/
 *.pyc
 *#
 *~

.travis.yml

@@ -1,12 +1,10 @@
 sudo: false
 language: python
-python:
-  - 2.7
-  - 3.4
-  - 3.5
+python: 3.5
 cache:
   directories:
     - $HOME/.cache/pip
+    - $TRAVIS_BUILD_DIR/.tox
 before_install:
   - mkdir -p $HOME/opt/local/bin
   - export PATH=$HOME/opt/local/bin:$PATH
@@ -15,8 +13,8 @@ before_install:
   - cp scripts/slackbot-test-ctl $HOME/opt/local/bin
   - slackbot-test-ctl init
   - slackbot-test-ctl startproxy
-install: pip install -r requirements.txt
-script: py.test -s -vv
+install: pip install tox
+script: tox
 deploy:
   provider: pypi
   distributions: sdist bdist_wheel

CONTRIBUTING.md

@@ -93,6 +93,8 @@ $ py.test
 
 If you're signed into slack, you'll see your user account and bot account chatting with each other as the tests run.
 
+Tox is also available. If your system has Python 2.7, 3.4, and 3.5 installed, installing and running tox will automatically manage the virtual Python environments and dependencies for you.
+
 ### Configure Travis
 
 Log in to Travis and enable tests for your slackbot fork. Open Travis settings. You must add the following environment variables, which should correlate to settings in `slackbot_test_settings.py`:

scripts/slackbot-test-ctl

@@ -49,7 +49,7 @@ main() {
       pkill -f "ssserver -c $ssconfig"
       ;;
     run)
-       proxychains4 -f $proxychainsconfig "$@"
+       exec proxychains4 -f $proxychainsconfig "$@"
       ;;
     *)
       echo "WARNING: unknown command $action"

tox.ini

@@ -0,0 +1,7 @@
+[tox]
+envlist = py27,py34,py35
+[testenv]
+deps =
+    pytest
+commands = py.test -s -vv
+passenv = SLACKBOT_* TRAVIS