Add cloudron purpose to appstore login/signup flow

src/views/appstore.html

@@ -225,6 +225,11 @@
                 </div>
             </div>
 
+            <div class="form-group">
+              <label class="control-label">Purpose</label>
+              <select class="form-control" ng-model="appstoreLogin.purpose" ng-options="a for a in appstoreLogin.purposes" required></select>
+            </div>
+
             <div class="checkbox">
                 <label>
                     <input type="checkbox" ng-model="appstoreLogin.termsAccepted">I accept the Cloudron <a href="https://cloudron.io/legal/license.html" target="_blank">license</a>