update yarn.lock

yarn.lock

@@ -2840,7 +2840,7 @@ fs-extra@^3.0.1:
     jsonfile "^3.0.0"
     universalify "^0.1.0"
 
-fs-extra@^4.0.1:
+fs-extra@^4.0.1, fs-extra@^4.0.2:
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-4.0.2.tgz#f91704c53d1b461f893452b0c307d9997647ab6b"
   dependencies:
@@ -7127,20 +7127,20 @@ wordwrap@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-1.0.0.tgz#27584810891456a4171c8d0226441ade90cbcaeb"
 
-workbox-build@^1.3.0:
-  version "1.3.0"
-  resolved "https://registry.yarnpkg.com/workbox-build/-/workbox-build-1.3.0.tgz#00e9a02424214cf9dd41cba761f296bb556b6c8a"
+workbox-build@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/workbox-build/-/workbox-build-2.1.1.tgz#9d92bca4a760e44799346fac1efb41ddb2f7f4b1"
   dependencies:
     chalk "^1.1.3"
     fs-extra "^3.0.1"
     glob "^7.1.1"
     lodash.template "^4.4.0"
     mkdirp "^0.5.1"
-    workbox-sw "^1.3.0"
+    workbox-sw "^2.1.1"
 
-workbox-sw@^1.3.0:
-  version "1.3.0"
-  resolved "https://registry.yarnpkg.com/workbox-sw/-/workbox-sw-1.3.0.tgz#60f59207d4ce8035c6af978fd5bd2007beca0bb7"
+workbox-sw@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/workbox-sw/-/workbox-sw-2.1.1.tgz#26482d97f70fd4e70fce8c6cd520b4395df98bf8"
 
 worker-farm@^1.3.1:
   version "1.5.2"