fix GA: runs-on ubuntu-latest and use container for 'catkin' check

Author: k-okada

.github/workflows/config.yml

@@ -30,7 +30,7 @@ jobs:
           - DOCKER_IMAGE: osrf/debian_arm64:stretch
       fail-fast: false
 
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     timeout-minutes: 90
 
     name: linux
@@ -53,7 +53,8 @@ jobs:
           docker run --rm $QEMU_VOLUME -v $CI_SOURCE_PATH:$CI_SOURCE_PATH -e "DOCKER_IMAGE=$DOCKER_IMAGE" -e "COLLISION_LIB=$COLLISION_LIB" -e "CI_SOURCE_PATH=$CI_SOURCE_PATH" -e "HOME=$HOME" -t $DOCKER_IMAGE sh -c "cd $CI_SOURCE_PATH; ./.travis.sh"
 
   catkin:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
+    container: ubuntu:18.04
     timeout-minutes: 60
 
     steps: