Separate coverage job from the testing

Author: duckontheweb

.github/workflows/continuous-integration.yml

@@ -38,23 +38,23 @@ jobs:
         with:
           path: ~/.cache/pip
           # Cache based on OS, Python version, and dependency hash
-          key: test-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
+          key: pip-test-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
 
       - name: Cache dependencies (macOS)
         if: startsWith(runner.os, 'macOS')
         uses: actions/cache@v2
         with:
           path: ~/Library/Caches/pip
           # Cache based on OS, Python version, and dependency hash
-          key: test-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
+          key: pip-test-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
 
       - name: Cache dependencies (Windows)
         if: startsWith(runner.os, 'Windows')
         uses: actions/cache@v2
         with:
           path: ~\AppData\Local\pip\Cache
           # Cache based on OS, Python version, and dependency hash
-          key: pip-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
+          key: pip-test-${{ runner.os }}-python${{ matrix.python-version }}-${{ hashFiles('requirements-test.txt') }}
 
       - name: Install dependencies
         run: |
@@ -67,15 +67,46 @@ jobs:
         shell: bash
         env:
           TMPDIR: "${{ matrix.os == 'windows-latest' && 'D:\\a\\_temp' || '' }}"
+
+  coverage:
+    name: coverage
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.8"
+
+      - name: Cache dependencies
+        uses: actions/cache@v2
+        with:
+          path: ~/.cache/pip
+          # Cache based on OS, Python version, and dependency hash
+          key: pip-test-${{ runner.os }}-python3.8-${{ hashFiles('requirements-test.txt') }}
+      
+      - name: Install dependencies
+        run: |
+          pip install --upgrade pip
+          pip install -r requirements-test.txt
+          pip install -e ".[validation]"
+      
+      - name: Execute test suite
+        # --fail-under=0 ensures we publish the coverage regardless of whether it meets
+        # the minimum so we can use Codecov to evaluate gaps
+        run: |
+          coverage run --source=pystac/ -m unittest discover tests/
+          coverage xml --fail-under=0
       
       - name: Upload All coverage to Codecov
         uses: codecov/codecov-action@v1
-        # Only upload this once...
-        if: ${{ matrix.os == 'ubuntu-latest' && matrix.python-version == '3.8'}}
+        if: ${{ env.GITHUB_REPOSITORY }} == 'stac-utils/pystac'
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./coverage.xml
           fail_ci_if_error: false 
+
   lint:
     runs-on: ubuntu-latest
     strategy: