Add melodic ci job

I took the liberty to open a MR to discuss this.

Added 71a4e0c1 to restrict execution of melodic jobs to branches named melodic-devel, and kinetic jobs to any other. This is far from ideal, because branches based of melodic-devel will still run the kinetic job. Maybe we should use some prefix for melodic-based branches while this is not the default supported distro?

Ran a couple of test jobs (one for melodic-devel named branch and one for other) and it seems fine.

.gitlab-industrial-ci-kinetic-no-rosinstall.yml

@@ -38,6 +38,18 @@ industrial_ci_kinetic:
     DOCKER_IMAGE: "${ARTIFACT_DOCKER_URL}/flexbotics-base-devel:${ROS_DISTRO}"
   except:
     - tags
+    - melodic-devel
+
+industrial_ci_melodic:
+  extends: .industrial_ci
+  variables:
+    ROS_DISTRO: melodic
+    DOCKER_IMAGE: "${ARTIFACT_DOCKER_URL}/flexbotics-base-devel:${ROS_DISTRO}"
+  only:
+    - melodic-devel
+  except:
+    - tags
+  allow_failure: yes
 
 industrial_ci_kinetic_deploy:
   extends: .industrial_ci