(core) add CI github action for grist-core

Summary:
Activate CI for grist-core using github actions.  Can be improved
with caching but starting simple.

Test Plan: tested in a fork of grist-core

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2771

.github/workflows/docker.yml

@@ -0,0 +1,22 @@
+name: Push Docker image
+
+on:
+  release:
+    types: [published]
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  push_to_registry:
+    name: Push Docker image to Docker Hub
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v2
+      - name: Push to Docker Hub
+        uses: docker/build-push-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+          repository: gristlabs/grist
+          tag_with_ref: true

.github/workflows/main.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+  # Allows running this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [2.7]
+        node-version: [10.x]
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Python packages
+        run: |
+          pip install virtualenv
+          yarn run install:python
+
+      - name: Install Node.js packages
+        run: yarn install
+
+      - name: Build Node.js code
+        run: yarn run build:prod
+
+      - name: Run tests
+        run: VERBOSE=1 DEBUG=1 MOCHA_WEBDRIVER_HEADLESS=1 yarn run test

buildtools/prepare_python.sh

@@ -1,8 +1,11 @@
 #!/bin/bash
 
+set -e
+
 if [ ! -e venv ]; then
   virtualenv -ppython2.7 venv
 fi
 
 . venv/bin/activate
+
 pip install --no-deps -r sandbox/requirements.txt