Upgrade systemjs to 0.21.3 (from 0.20.19)

Author: bdukes

package.json

@@ -66,7 +66,7 @@
     "select2": "4.0.5",
     "spectrum-colorpicker": "1.8.0",
     "swiper": "4.2.6",
-    "systemjs": "0.20.19",
+    "systemjs": "0.21.3",
     "tableexport": "4.0.11",
     "tinymce": "4.7.12",
     "tota11y": "0.1.6",

yarn.lock

@@ -5475,9 +5475,9 @@ swiper@4.2.6:
     dom7 "^2.0.5"
     ssr-window "^1.0.0"
 
-systemjs@0.20.19:
-  version "0.20.19"
-  resolved "https://registry.yarnpkg.com/systemjs/-/systemjs-0.20.19.tgz#c2b9e79c19f4bea53a19b1ed3f974ffb463be949"
+systemjs@0.21.3:
+  version "0.21.3"
+  resolved "https://registry.yarnpkg.com/systemjs/-/systemjs-0.21.3.tgz#76467a34a9a12ead3b11028a27345f7649e46204"
 
 tableexport@4.0.11:
   version "4.0.11"