Update travis CI for merge

Author: ruffsl

.travis.yml

@@ -11,8 +11,9 @@ install:
 
 env:
   # ros2
-  - HUB_REPO=ros2   HUB_RELEASE=ardent    HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=xenial
-  - HUB_REPO=ros2   HUB_RELEASE=bouncy    HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=bionic
+  - HUB_REPO=ros   HUB_RELEASE=crystal   HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=bionic
+  - HUB_REPO=ros   HUB_RELEASE=bouncy    HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=bionic
+  - HUB_REPO=ros   HUB_RELEASE=ardent    HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=xenial
   # ros
   - HUB_REPO=ros    HUB_RELEASE=melodic HUB_OS_NAME=ubuntu HUB_OS_CODE_NAME=bionic
   - HUB_REPO=ros    HUB_RELEASE=melodic HUB_OS_NAME=debian HUB_OS_CODE_NAME=stretch