CI: shorten names

.github/workflows/build.yml

@@ -7,14 +7,14 @@ on:
     branches: [ master ]
 
 jobs:
-  build-melodic:
+  melodic:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
       - name: Native Melodic build
         run: |
           docker run --rm -v $(pwd):/root/catkin_ws/src/clover ros:melodic-ros-base /root/catkin_ws/src/clover/builder/standalone-install.sh
-  build-noetic:
+  noetic:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2