Bump acorn from 5.7.3 to 5.7.4

Bumps [acorn](https://github.com/acornjs/acorn) from 5.7.3 to 5.7.4.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](acornjs/acorn@5.7.3...5.7.4)

Signed-off-by: dependabot[bot] <support@github.com>

yarn.lock

@@ -779,8 +779,8 @@ acorn-jsx@^5.0.0:
   resolved "http://registry.npm.taobao.org/acorn-jsx/download/acorn-jsx-5.0.1.tgz#32a064fd925429216a09b141102bfdd185fae40e"
 
 acorn@^5.0.0, acorn@^5.6.2, acorn@^5.7.3:
-  version "5.7.3"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.3.tgz#67aa231bf8812974b85235a96771eb6bd07ea279"
+  version "5.7.4"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.7.4.tgz#3e8d8a9947d0599a1796d10225d7432f4a4acf5e"
 
 acorn@^6.0.2:
   version "6.0.4"
@@ -1049,23 +1049,6 @@ babel-generator@^6.18.0:
     source-map "^0.5.7"
     trim-right "^1.0.1"
 
-babel-helper-bindify-decorators@^6.24.1:
-  version "6.24.1"
-  resolved "https://registry.yarnpkg.com/babel-helper-bindify-decorators/-/babel-helper-bindify-decorators-6.24.1.tgz#14c19e5f142d7b47f19a52431e52b1ccbc40a330"
-  dependencies:
-    babel-runtime "^6.22.0"
-    babel-traverse "^6.24.1"
-    babel-types "^6.24.1"
-
-babel-helper-explode-class@^6.24.1:
-  version "6.24.1"
-  resolved "https://registry.yarnpkg.com/babel-helper-explode-class/-/babel-helper-explode-class-6.24.1.tgz#7dc2a3910dee007056e1e31d640ced3d54eaa9eb"
-  dependencies:
-    babel-helper-bindify-decorators "^6.24.1"
-    babel-runtime "^6.22.0"
-    babel-traverse "^6.24.1"
-    babel-types "^6.24.1"
-
 babel-loader@^8.0.4:
   version "8.0.4"
   resolved "http://registry.npm.taobao.org/babel-loader/download/babel-loader-8.0.4.tgz#7bbf20cbe4560629e2e41534147692d3fecbdce6"
@@ -1081,28 +1064,6 @@ babel-messages@^6.23.0:
   dependencies:
     babel-runtime "^6.22.0"
 
-babel-plugin-syntax-decorators@^6.1.18, babel-plugin-syntax-decorators@^6.13.0:
-  version "6.13.0"
-  resolved "https://registry.yarnpkg.com/babel-plugin-syntax-decorators/-/babel-plugin-syntax-decorators-6.13.0.tgz#312563b4dbde3cc806cee3e416cceeaddd11ac0b"
-
-babel-plugin-transform-decorators-legacy@^1.3.5:
-  version "1.3.5"
-  resolved "http://registry.npm.taobao.org/babel-plugin-transform-decorators-legacy/download/babel-plugin-transform-decorators-legacy-1.3.5.tgz#0e492dffa0edd70529072887f8aa86d4dd8b40a1"
-  dependencies:
-    babel-plugin-syntax-decorators "^6.1.18"
-    babel-runtime "^6.2.0"
-    babel-template "^6.3.0"
-
-babel-plugin-transform-decorators@^6.24.1:
-  version "6.24.1"
-  resolved "https://registry.yarnpkg.com/babel-plugin-transform-decorators/-/babel-plugin-transform-decorators-6.24.1.tgz#788013d8f8c6b5222bdf7b344390dfd77569e24d"
-  dependencies:
-    babel-helper-explode-class "^6.24.1"
-    babel-plugin-syntax-decorators "^6.13.0"
-    babel-runtime "^6.22.0"
-    babel-template "^6.24.1"
-    babel-types "^6.24.1"
-
 babel-polyfill@^6.3.14:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-polyfill/-/babel-polyfill-6.26.0.tgz#379937abc67d7895970adc621f284cd966cf2153"
@@ -1111,14 +1072,14 @@ babel-polyfill@^6.3.14:
     core-js "^2.5.0"
     regenerator-runtime "^0.10.5"
 
-babel-runtime@^6.0.0, babel-runtime@^6.2.0, babel-runtime@^6.22.0, babel-runtime@^6.26.0:
+babel-runtime@^6.0.0, babel-runtime@^6.22.0, babel-runtime@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.26.0.tgz#965c7058668e82b55d7bfe04ff2337bc8b5647fe"
   dependencies:
     core-js "^2.4.0"
     regenerator-runtime "^0.11.0"
 
-babel-template@^6.16.0, babel-template@^6.24.1, babel-template@^6.3.0:
+babel-template@^6.16.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-template/-/babel-template-6.26.0.tgz#de03e2d16396b069f46dd9fff8521fb1a0e35e02"
   dependencies:
@@ -1128,7 +1089,7 @@ babel-template@^6.16.0, babel-template@^6.24.1, babel-template@^6.3.0:
     babylon "^6.18.0"
     lodash "^4.17.4"
 
-babel-traverse@^6.18.0, babel-traverse@^6.24.1, babel-traverse@^6.26.0:
+babel-traverse@^6.18.0, babel-traverse@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-traverse/-/babel-traverse-6.26.0.tgz#46a9cbd7edcc62c8e5c064e2d2d8d0f4035766ee"
   dependencies:
@@ -1142,7 +1103,7 @@ babel-traverse@^6.18.0, babel-traverse@^6.24.1, babel-traverse@^6.26.0:
     invariant "^2.2.2"
     lodash "^4.17.4"
 
-babel-types@^6.18.0, babel-types@^6.24.1, babel-types@^6.26.0:
+babel-types@^6.18.0, babel-types@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-types/-/babel-types-6.26.0.tgz#a3b073f94ab49eb6fa55cd65227a334380632497"
   dependencies: