bump parallelism to 3 in test-jasmine2

Author: etpinard

.circleci/config.yml

@@ -53,7 +53,7 @@ jobs:
     docker:
       # need '-browsers' version to test in real (xvfb-wrapped) browsers
       - image: circleci/node:10.9.0-browsers
-    parallelism: 2
+    parallelism: 3
     working_directory: ~/plotly.js
     steps:
       - attach_workspace: