chore(ci): Remove windows from test matrix

Ember does not test against windows, neither should we. 

As discussed here #240 (comment)

Author: evoactivity

.github/workflows/ci.yml

@@ -15,24 +15,26 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
-          node-version: 10.x
-
-      - run: yarn install --frozen-lockfile --non-interactive
-      - run: yarn lint:js
+          node-version: 12.x
+          cache: yarn
+      - name: install dependencies
+        run: yarn install --frozen-lockfile --non-interactive
+      - name: linting
+        run: yarn lint
 
   tests:
     name: 'Tests: ${{ matrix.os }}'
     runs-on: '${{ matrix.os }}-latest'
 
     strategy:
       matrix:
-        os: [ubuntu, macOS, windows]
+        os: [ubuntu, macOS]
 
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
-          node-version: 10.x
+          node-version: 12.x
 
       - run: yarn install --frozen-lockfile --non-interactive
       - run: yarn test