Move to GitHub Actions Only

- Unittests + black check now run by GitHub Actions
- TravisCI is very slow these days

.github/workflows/ci.yml

@@ -0,0 +1,37 @@
+name: ci
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: Running python ${{ matrix.python-version }} on ${{matrix.os}}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        python-version: [3.6, 3.7, 3.8, 3.9]
+        os: [ubuntu-latest]
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Update pip, setuptools + wheel
+      run: |
+        python -m pip install --upgrade pip setuptools wheel
+
+    - name: Install flake8-bugbear w/dev extra install
+      run: |
+        python -m pip install .[dev]
+
+    - name: Run Unittests
+      run: |
+        coverage run tests/test_bugbear.py
+        coverage report -m
+
+    - name: Check formatting
+      run: |
+        black --check .