upgrade worker-loader to remove tappable deprecation warnings

package.json

@@ -96,7 +96,7 @@
     "webpack-bundle-analyzer": "^2.11.1",
     "webpack-cli": "^2.1.2",
     "webpack-stats-plugin": "^0.2.1",
-    "worker-loader": "^1.1.1"
+    "worker-loader": "^2.0.0"
   },
   "devDependencies": {
     "axios-mock-adapter": "^1.15.0",

yarn.lock

@@ -9049,9 +9049,9 @@ worker-farm@^1.5.2:
     errno "^0.1.4"
     xtend "^4.0.1"
 
-worker-loader@^1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/worker-loader/-/worker-loader-1.1.1.tgz#920d74ddac6816fc635392653ed8b4af1929fd92"
+worker-loader@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/worker-loader/-/worker-loader-2.0.0.tgz#45fda3ef76aca815771a89107399ee4119b430ac"
   dependencies:
     loader-utils "^1.0.0"
     schema-utils "^0.4.0"