Exposing ports to the host causes the tests to be flaky.

ERROR: for db  Cannot start service db: driver failed programming external connectivity on endpoint db (7a7976dfaf7ead9b104702282b06bab15691f264bff93806abd17ddf10490a3a): Error starting userland proxy: listen tcp 0.0.0.0:3306: bind: address already in use

I think this happens because other tests are using the same port
ocassionally. Moving to using a separate test docker-compose file
so we don't have to mest with the development travis file.

.travis.yml

@@ -8,15 +8,13 @@ services:
 
 sudo: required
 
-# 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
     - node_modules
     - course_discovery/static/bower_components
 
 before_install:
-    - docker-compose -f docker-compose.yml up -d
+    - docker-compose -f .travis/docker-compose-travis.yml up -d
 
 script:
     - docker exec course-discovery /edx/app/discovery/discovery/.travis/run_tests.sh

.travis/docker-compose-travis.yml

+version: "2"
+
+services:
+  db:
+    image: mysql:5.6
+    container_name: db
+    command: mysqld --character-set-server=utf8 --collation-server=utf8_general_ci
+    environment:
+      MYSQL_ROOT_PASSWORD: ""
+      MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
+      MYSQL_USER: "discov001"
+      MYSQL_PASSWORD: "password"
+      MYSQL_DATABASE: "discovery"
+  es:
+    image: elasticsearch:1.5.2
+    container_name: es
+  memcache:
+    image: memcached:1.4.24
+    container_name: memcache
+  course-discovery:
+    # Uncomment this line to use the official course-discovery base image
+    image: edxops/course-discovery:bilal-test
+
+    # Uncomment the next two lines to build from a local configuration repo
+    # build: ../configuration/docker/build/discovery/
+
+    container_name: course-discovery
+    volumes:
+      - ..:/edx/app/discovery/discovery
+      - ../course_discovery/media:/edx/var/discovery/media
+      - ../course_discovery/assets:/edx/var/discovery/staticfiles
+    command: tail -f /dev/null
+    depends_on:
+      - "db"
+      - "es"
+      - "memcache"
+    environment:
+      TEST_ELASTICSEARCH_URL: "http://es:9200"
+      ENABLE_DJANGO_TOOLBAR: 1

docker-compose.yml

@@ -33,7 +33,7 @@ services:
 
   course-discovery:
     # Uncomment this line to use the official course-discovery base image
-    image: edxops/course-discovery:bilal-test
+    image: edxops/course-discovery:latest
 
     # Uncomment the next two lines to build from a local configuration repo
     # build: ../configuration/docker/build/discovery/
@@ -55,4 +55,3 @@ services:
       - "18381:18381"
       - "8381:8381"
       - "48381:48381"
-    command: tail -f /dev/null