Run ecomworker tests on 16.04.

We now use a docker container that more closely matches production.

.travis.yml

 language: python
 python:
     - '2.7'
-sudo: false
+sudo: required
+
+services:
+    - docker
+
+before_install:
+    - docker-compose -f .travis/docker-compose-travis.yml up -d
 
-# Cache the pip directory. "cache: pip" doesn't work due to install override.
-# See https://github.com/travis-ci/travis-ci/issues/3239.
-cache:
-    - directories:
-        - $HOME/.cache/pip
-install:
-    - pip install -U pip wheel
-    - pip install -U codecov
-    - make requirements
 script:
-    - make validate
+    - docker exec ecomworker /edx/app/ecomworker/ecomworker/.travis/run_tests.sh
+
 after_success:
+    - pip install -U codecov
+    - docker exec ecomworker /edx/app/ecomworker/ecomworker/.travis/run_coverage.sh
     - codecov
 
 deploy:

.travis/docker-compose-travis.yml

+version: "2"
+
+services:
+  ecomworker:
+    image: edxops/ecomworker:latest
+
+    container_name: ecomworker
+    volumes:
+      - ..:/edx/app/ecomworker/ecomworker
+    command: tail -f /dev/null

.travis/run_coverage.sh

+#!/bin/bash -xe
+. /edx/app/ecomworker/venvs/ecomworker/bin/activate
+cd /edx/app/ecomworker/ecomworker
+coverage xml

.travis/run_tests.sh

+#!/bin/bash -xe
+. /edx/app/ecomworker/venvs/ecomworker/bin/activate
+
+cd /edx/app/ecomworker/ecomworker
+
+make requirements
+
+# Run validation
+make validate