use test-utils beta-20

package.json

@@ -33,7 +33,7 @@
     "@babel/plugin-transform-runtime": "^7.2.0",
     "@babel/preset-env": "^7.3.1",
     "@babel/runtime": "^7.3.1",
-    "@vue/test-utils": "^1.0.0-beta.29",
+    "@vue/test-utils": "1.0.0-beta.20",
     "babel-core": "^7.0.0-bridge.0",
     "babel-loader": "^8.0.0",
     "chokidar": "^2.0.4",

yarn.lock

@@ -770,12 +770,11 @@
   resolved "https://registry.yarnpkg.com/@vue/preload-webpack-plugin/-/preload-webpack-plugin-1.1.0.tgz#d768dba004261c029b53a77c5ea2d5f9ee4f3cce"
   integrity sha512-rcn2KhSHESBFMPj5vc5X2pI9bcBNQQixvJXhD5gZ4rN2iym/uH2qfDSQfUS5+qwiz0a85TCkeUs6w6jxFDudbw==
 
-"@vue/test-utils@^1.0.0-beta.29":
-  version "1.0.0-beta.29"
-  resolved "https://registry.yarnpkg.com/@vue/test-utils/-/test-utils-1.0.0-beta.29.tgz#c942cf25e891cf081b6a03332b4ae1ef430726f0"
-  integrity sha512-yX4sxEIHh4M9yAbLA/ikpEnGKMNBCnoX98xE1RwxfhQVcn0MaXNSj1Qmac+ZydTj6VBSEVukchBogXBTwc+9iA==
+"@vue/test-utils@1.0.0-beta.20":
+  version "1.0.0-beta.20"
+  resolved "https://registry.yarnpkg.com/@vue/test-utils/-/test-utils-1.0.0-beta.20.tgz#ef4505341b802f3de1c06b3cb8651378c87371fa"
+  integrity sha1-70UFNBuALz3hwGs8uGUTeMhzcfo=
   dependencies:
-    dom-event-types "^1.0.0"
     lodash "^4.17.4"
 
 "@vue/web-component-wrapper@^1.2.0":
@@ -3023,11 +3022,6 @@ dom-converter@~0.1:
   dependencies:
     utila "~0.3"
 
-dom-event-types@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/dom-event-types/-/dom-event-types-1.0.0.tgz#5830a0a29e1bf837fe50a70cd80a597232813cae"
-  integrity sha512-2G2Vwi2zXTHBGqXHsJ4+ak/iP0N8Ar+G8a7LiD2oup5o4sQWytwqqrZu/O6hIMV0KMID2PL69OhpshLO0n7UJQ==
-
 dom-serializer@0, dom-serializer@~0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/dom-serializer/-/dom-serializer-0.1.0.tgz#073c697546ce0780ce23be4a28e293e40bc30c82"