Separate out black check

Author: terriko

.github/workflows/pythonapp.yml

@@ -3,13 +3,32 @@ name: cve-bin-tool
 on: [push, pull_request]
 
 jobs:
+  black_check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.7
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+    - name: Lint with black
+      run: |
+        pip install black
+        black --check cve_bin_tool/
+        black --check test/
+
   build:
 
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
          os: [ubuntu-latest, windows-latest]
-         python: [3.6, 3.7]
+         python: [2.7, 3.6, 3.7]
+      fail-fast: false
     steps:
     - uses: actions/checkout@v1
     - name: Set up Python
@@ -20,11 +39,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-    - name: Lint with black
-      run: |
-        pip install black
-        black --check cve_bin_tool/
-        black --check test/
     - name: Run tests
       run: |
         ACTIONS=1 python setup.py test