Install ARM gcc

Signed-off-by: Daniel Egger <[email protected]>

Author: therealprof

cortex-m-rt/.github/workflows/ci.yml

@@ -22,6 +22,9 @@ jobs:
             experimental: true
 
     steps:
+      - uses: fiam/arm-none-eabi-gcc@v1
+        with:
+          release: '7-2018-q2'
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with: