Fix MySQL compatibility in the docker images. (#140)

* Fix MySQL compatibility in the docker images.

* Test the containers with MySQL containers too!

.travis.yml

@@ -5,6 +5,10 @@ services:
 
 language: python
 
+env:
+  - DB=postgres
+  - DB=mysql
+
 install:
   - docker --version
   - ./build.sh
@@ -13,14 +17,6 @@ install:
 
 before_script:
   - sh tests/generate_tests.sh
-  - docker-compose -f docker-compose.yaml -f docker-test.yaml up -d
-  - docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' mailman-core
-  - docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' mailman-web
-  - docker-compose ps
-  - sleep 30
-  - docker ps
-  - docker logs mailman-web
-  - docker logs mailman-core
 
 script:
   - sh tests/test.sh