upgrade tinymce-light-skin to 1.2.5

fixes CNVS-37316

fixes issue cause by a const not-transpiled to var

test plan:
- pages with tinymce don't have non-transpiled const

Change-Id: I2ff0bdae30921780b376fdb7ec7a5a128d495f7b
Reviewed-on: https://gerrit.instructure.com/114170
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Tested-by: Jenkins
Reviewed-by: brian kirkby <bkirkby@instructure.com>
QA-Review: Brent Burgoyne <bburgoyne@instructure.com>
Product-Review: Brent Burgoyne <bburgoyne@instructure.com>

package.json

@@ -125,7 +125,7 @@
     "tablesorter": "^2.28.5",
     "through2": "^2.0.3",
     "timezone": "1.0.6",
-    "tinymce-light-skin": "1.2.4",
+    "tinymce-light-skin": "1.2.5",
     "webpack": "2.2.1",
     "webpack-cleanup-plugin": "^0.5.1",
     "webpack-manifest-plugin": "^1.0.1",

yarn.lock

@@ -7747,9 +7747,9 @@ tinycolor2@1.4.1:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/tinycolor2/-/tinycolor2-1.4.1.tgz#f4fad333447bc0b07d4dc8e9209d8f39a8ac77e8"
 
-tinymce-light-skin@1.2.4, tinymce-light-skin@~1.2.4:
-  version "1.2.4"
-  resolved "https://registry.yarnpkg.com/tinymce-light-skin/-/tinymce-light-skin-1.2.4.tgz#66c380aef453d886428cdc93d9a79e0e1500bb9a"
+tinymce-light-skin@1.2.5, tinymce-light-skin@~1.2.4:
+  version "1.2.5"
+  resolved "https://registry.yarnpkg.com/tinymce-light-skin/-/tinymce-light-skin-1.2.5.tgz#3d37f1628ef737432c725eed1b226b6c8d275b0c"
 
 tinymce@4.5.7, tinymce@~4.5.3:
   version "4.5.7"