Add yarn matrix (#70)

.github/workflows/push-master.yml

@@ -5,8 +5,11 @@ on:
       - master
 
 jobs:
-  build_code:
-    name: Build Code
+  master:
+    strategy:
+      matrix:
+        step: ['build:release']
+    name: ${{ matrix.step }}
     if: "! contains(github.event.head_commit.message, '[CI Skip]')"
     runs-on: ubuntu-latest
     steps:
@@ -23,9 +26,8 @@ jobs:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
       run: |
-        rustup toolchain install nightly
         yarn install --immutable | grep -v 'YN0013'
-        yarn polkadot-ci-ghact-build
+        yarn ${{ matrix.step }}
 
   dummy:
     name: Dummy