Add WebGL support to Chromium on Cypress (#109)

Following cypress-io/cypress#1194 (comment)

Work on #107.

.gitignore

@@ -1,7 +1,6 @@
 node_modules
 yarn.lock
 npm-debug.log
-cypress/plugins
 cypress/screenshots
 cypress/videos
 .idea/

cypress/plugins/index.js

@@ -0,0 +1,16 @@
+// You can read more here:
+// https://on.cypress.io/plugins-guide
+// ***********************************************************
+
+// This function is called when a project is opened or re-opened (e.g. due to
+// the project's config changing)
+//
+module.exports = (on, config) => {
+  on('before:browser:launch', (browser = {}, args) => {
+    if (browser.name === 'chromium') {
+      const newArgs = args.filter(arg => arg !== '--disable-gpu');
+      newArgs.push('--ignore-gpu-blacklist');
+      return newArgs;
+    }
+  });
+};