don't run Github tests unless process.env.TEST8BIT_GITHUB_TOKEN exists

test/cli/testgithub.js

@@ -1,5 +1,10 @@
 "use strict";
 
+// don't run unless Github token exists
+if (!process.env.TEST8BIT_GITHUB_TOKEN) {
+  return;
+}
+
 var vm = require('vm');
 var fs = require('fs');
 var assert = require('assert');