chore(gen): make sure users are using yo >= 1.7.1

Author: Awk34

script-base.js

@@ -15,6 +15,14 @@ var Generator = module.exports = function Generator() {
 
   this.lodash = lodash;
 
+  if(!process.env.CI) {
+    yoCheckPromise = genUtils.runCmd('yo --version').then(stdout => {
+      if(!semver.satisfies(semver.clean(stdout), '>= 1.7.1')) {
+        throw new Error('ERROR: You need to update yo to at least 1.7.1 (npm i -g yo)');
+      }
+    });
+  } // CI won't have yo installed
+
   try {
     this.appname = require(path.join(process.cwd(), 'bower.json')).name;
   } catch (e) {