apply matrix.os to runs-on key

responses/08_new-job.md

@@ -42,7 +42,7 @@ This will allow us to separate the build and test functions of our workflow into
 4. In the newly created `test` job, include the following portions of your existing workflow:
     ```yaml
     test:
-      runs-on: ubuntu-latest
+      runs-on: ${{ matrix.os }}
       strategy:
         matrix:
           os: [ubuntu-latest, windows-2016]

responses/11_use-download.md

@@ -21,14 +21,14 @@ _You can follow the manual steps below, or accept the suggestions in the followi
     ```yaml
       test:
         needs: build
-        runs-on: ubuntu-latest
+        runs-on: ${{ matrix.os }}
         ...
     ```
 1. Add a step to your `test` job that uses the `download-artifacts` action.
     ```yaml
       test:
         needs: build
-        runs-on: ubuntu-latest
+        runs-on: ${{ matrix.os }}
         ...
         steps:
         - uses: actions/checkout@v2