ci: migrate to GitHub Actions (#137)

Author: felixfbecker

.github/workflows/build.yml

@@ -0,0 +1,26 @@
+name: build
+
+on: [push, pull_request]
+
+env:
+  FORCE_COLOR: 3
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: '14.x'
+      - run: yarn
+      - run: yarn run prettier-check
+      - run: yarn run eslint
+      - run: yarn run build
+      - name: release
+        if: github.repository_owner == 'sourcegraph' && github.event_name == 'push' && github.ref == 'refs/heads/master'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          VSCE_TOKEN: ${{ secrets.VSCE_TOKEN }}
+        run: yarn run semantic-release

.travis.yml

@@ -1,7 +1,7 @@
 .editorconfig
+.github/**
 .gitignore
 .prettierignore
-.travis.yml
 .vscode-test/**
 .vscode/**
 **/*.map

.vscodeignore

@@ -1,6 +1,6 @@
 # Sourcegraph for Visual Studio Code
 
-[![vs marketplace](https://img.shields.io/vscode-marketplace/v/sourcegraph.sourcegraph.svg?label=vs%20marketplace)](https://marketplace.visualstudio.com/items?itemName=sourcegraph.sourcegraph) [![downloads](https://img.shields.io/vscode-marketplace/d/sourcegraph.sourcegraph.svg)](https://marketplace.visualstudio.com/items?itemName=sourcegraph.sourcegraph) [![build](https://travis-ci.com/sourcegraph/sourcegraph-vscode.svg?branch=master)](https://travis-ci.com/sourcegraph/sourcegraph-vscode) [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
+[![vs marketplace](https://img.shields.io/vscode-marketplace/v/sourcegraph.sourcegraph.svg?label=vs%20marketplace)](https://marketplace.visualstudio.com/items?itemName=sourcegraph.sourcegraph) [![downloads](https://img.shields.io/vscode-marketplace/d/sourcegraph.sourcegraph.svg)](https://marketplace.visualstudio.com/items?itemName=sourcegraph.sourcegraph) [![build](https://img.shields.io/github/workflow/status/sourcegraph/sourcegraph-vscode/build/master)](https://github.com/sourcegraph/sourcegraph-vscode/actions?query=branch%3Amaster+workflow%3Abuild) [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 
 The Sourcegraph extension for VS Code enables you to open and search code on Sourcegraph.com easily and efficiently.