Create GitHub action for testing

.github/workflows/CI.yml

@@ -0,0 +1,35 @@
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        julia-version: ['1.5.0']
+        python-version: ['3.6']
+        os: [ubuntu-latest, windows-latest]
+    
+    steps:
+      - uses: actions/checkout@v1.0.0
+      - name: "Set up Julia"
+        uses: julia-actions/setup-julia@v1.6.0
+        with:
+          version: ${{ matrix.julia-version }}
+      - name: "Set up Python"
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: "Install PySR"
+        run: |
+            python -m pip install --upgrade pip
+            python setup.py install
+        shell: bash
+      - name: "Run tests"
+        run: python test/test.py
+        shell: bash