upgrade webpack-dev-server to fix browser compatibility

see webpack/webpack-dev-server#1273
chalk/strip-ansi#22
sindresorhus/ama#446

package.json

@@ -81,7 +81,7 @@
     "vue-template-compiler": "^2.5.13",
     "webpack": "^3.10.0",
     "webpack-bundle-analyzer": "^2.9.0",
-    "webpack-dev-server": "^2.11.0",
+    "webpack-dev-server": "^2.11.1",
     "webpack-merge": "^0.14.1",
     "xhr": "^2.3.2"
   },

yarn.lock

@@ -7319,7 +7319,18 @@ socket.io@1.7.3:
     socket.io-client "1.7.3"
     socket.io-parser "2.3.1"
 
-sockjs-client@1.1.4, sockjs-client@^1.1.1:
+sockjs-client@1.1.5:
+  version "1.1.5"
+  resolved "https://registry.yarnpkg.com/sockjs-client/-/sockjs-client-1.1.5.tgz#1bb7c0f7222c40f42adf14f4442cbd1269771a83"
+  dependencies:
+    debug "^2.6.6"
+    eventsource "0.1.6"
+    faye-websocket "~0.11.0"
+    inherits "^2.0.1"
+    json3 "^3.3.2"
+    url-parse "^1.1.8"
+
+sockjs-client@^1.1.1:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/sockjs-client/-/sockjs-client-1.1.4.tgz#5babe386b775e4cf14e7520911452654016c8b12"
   dependencies:
@@ -8351,9 +8362,9 @@ webpack-dev-middleware@1.12.2, webpack-dev-middleware@^1.12.0, webpack-dev-middl
     range-parser "^1.0.3"
     time-stamp "^2.0.0"
 
-webpack-dev-server@^2.11.0:
-  version "2.11.0"
-  resolved "https://registry.yarnpkg.com/webpack-dev-server/-/webpack-dev-server-2.11.0.tgz#e9d4830ab7eb16c6f92ed68b92f6089027960e1b"
+webpack-dev-server@^2.11.1:
+  version "2.11.3"
+  resolved "https://registry.yarnpkg.com/webpack-dev-server/-/webpack-dev-server-2.11.3.tgz#3fd48a402164a6569d94d3d17f131432631b4873"
   dependencies:
     ansi-html "0.0.7"
     array-includes "^3.0.3"
@@ -8376,9 +8387,9 @@ webpack-dev-server@^2.11.0:
     selfsigned "^1.9.1"
     serve-index "^1.7.2"
     sockjs "0.3.19"
-    sockjs-client "1.1.4"
+    sockjs-client "1.1.5"
     spdy "^3.4.1"
-    strip-ansi "^4.0.0"
+    strip-ansi "^3.0.0"
     supports-color "^5.1.0"
     webpack-dev-middleware "1.12.2"
     yargs "6.6.0"