Also test doctests

Author: jonhoo

.github/workflows/coverage.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v2
       - name: Generate code coverage
         run: |
-          cargo tarpaulin --verbose --all-features --timeout 120 --out Xml
+          cargo tarpaulin --verbose --all-features --timeout 120 --run-types Doctests --run-types Tests --out Xml
       - name: Upload to codecov.io
         uses: codecov/codecov-action@v2
         with: