Configured CI to only calculate coverage for recommended Node version

- we seem to be getting some odd numbers when running c8 on Node 12, and
  it's causing our CI checks to fail
- even when we're adding tests, the coverage value goes down
- this is disrupting the team from shipping, so we need to change that
- this commit alters the setup to run unit tests w/ c8 for Node 16 unit
  tests, and without c8 for other versions
- `yarn test:unit` is kept the same for everyday use

.github/workflows/test.yml

@@ -111,7 +111,12 @@ jobs:
           cache: yarn
 
       - run: yarn
+
       - run: yarn test:unit
+        if: matrix.node == '16.13.0'
+
+      - run: yarn test:unit:base
+        if: matrix.node != '16.13.0'
 
       - uses: codecov/codecov-action@v2
 

package.json

@@ -29,7 +29,8 @@
     "test": "mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js --timeout=60000",
     "test:all": "yarn test:unit && yarn test:integration && yarn test:e2e && yarn lint",
     "test:debug": "DEBUG=ghost:test* yarn test",
-    "test:unit": "c8 mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js './test/unit' --timeout=2000",
+    "test:unit": "c8 yarn test:unit:base",
+    "test:unit:base": "mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js './test/unit' --timeout=2000",
     "test:integration": "mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js  './test/integration' --timeout=5000",
     "test:e2e": "mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js './test/e2e-api' './test/e2e-frontend' './test/e2e-server' --timeout=10000",
     "test:regression": "mocha --require=./test/utils/overrides.js --exit --trace-warnings --recursive --extension=test.js  './test/regression' --timeout=60000",