Update dependency uglifyjs-webpack-plugin to v2.1.2

Author: renovate-bot

package.json

@@ -66,7 +66,7 @@
     "react-codemirror2": "5.1.0",
     "react-dom": "16.8.3",
     "react-test-renderer": "16.8.3",
-    "uglifyjs-webpack-plugin": "2.1.1",
+    "uglifyjs-webpack-plugin": "2.1.2",
     "webpack": "3.12.0",
     "webpack-dev-server": "2.11.3"
   },

yarn.lock

@@ -7782,9 +7782,9 @@ uglify-to-browserify@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/uglify-to-browserify/-/uglify-to-browserify-1.0.2.tgz#6e0924d6bda6b5afe349e39a6d632850a0f882b7"
 
-[email protected].1:
-  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/uglifyjs-webpack-plugin/-/uglifyjs-webpack-plugin-2.1.1.tgz#6937d7513a37280d4792f1fb536bef35e08e420a"
+[email protected].2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/uglifyjs-webpack-plugin/-/uglifyjs-webpack-plugin-2.1.2.tgz#70e5c38fb2d35ee887949c2a0adb2656c23296d5"
   dependencies:
     cacache "^11.2.0"
     find-cache-dir "^2.0.0"