Fix setup-buildx test workflow

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/setup-buildx-test.yml

@@ -19,10 +19,10 @@ jobs:
         uses: actions/checkout@v2.3.1
       -
         name: Install
-        run: yarn install
+        run: yarn --cwd ./setup-buildx/ install
       -
         name: Test
-        run: yarn run test
+        run: yarn --cwd ./setup-buildx/ run test
 #      -
 #        name: Upload coverage
 #        uses: codecov/codecov-action@v1.0.7