Configurable dev environment (#14869)

* Configurable dev environment

* Add a bit of documentation

* fixing gofmt

* A bit more doc

* Using  variable

* Adding license header

* Moving LDAP_DATA variable to the default-config.mk file

* Adding another docker-compose for the makefile to not brake anybody workflow

* Moving dejavu to the config

* Fixing docker-compose.makefile.yaml for dejavu

* Adding keycloak support to the dev environment

* Address PR review comments

* Removing minio from default docker images

* Changing the default version of mysql to the oldest supported (5.6)

* Change the restart option to no for the dev environment

* Fixing restart option

* Reverting unneded changes

* Restoring 5.7 to check if test passes

* Going back to 5.6 mysql image

* Fixing tests on mysql 5.6

* Skipping flaky test

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

docker-compose.yaml

@@ -51,8 +51,15 @@ services:
     ports:
       - "1358:1358"
     extends:
-        file: build/docker-compose.optional.yml
+        file: build/docker-compose.common.yml
         service: dejavu
+  keycloak:
+    container_name: mattermost-saml
+    ports:
+      - "8484:8080"
+    extends:
+        file: build/docker-compose.common.yml
+        service: keycloak
 
   start_dependencies:
     image: mattermost/mattermost-wait-for-dep:latest