Merge pull request #20 from pansyjs/dependabot/npm_and_yarn/acorn-6.4.2

chore(deps): bump acorn from 6.3.0 to 6.4.2

Author: wangxingkang

yarn.lock

@@ -2881,22 +2881,12 @@ acorn-walk@^7.1.1:
   resolved "https://registry.yarnpkg.com/acorn-walk/-/acorn-walk-7.2.0.tgz#0de889a601203909b0fbe07b8938dc21d2e967bc"
   integrity sha512-OPdCF6GsMIP+Az+aWfAAOEt2/+iVDKE7oy6lJ098aoe59oAmK76qV6Gw60SbZ8jHuG2wH058GF4pLFbYamYrVA==
 
-acorn@^6.0.1, acorn@^6.0.4:
-  version "6.4.1"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.1.tgz#531e58ba3f51b9dacb9a6646ca4debf5b14ca474"
-  integrity sha512-ZVA9k326Nwrj3Cj9jlh3wGFutC2ZornPNARZwsNYqQYgN0EsV2d53w5RN/co65Ohn4sUAUtb1rSUAOD6XN9idA==
+acorn@^6.0.1, acorn@^6.0.4, acorn@^6.1.1:
+  version "6.4.2"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.2.tgz#35866fd710528e92de10cf06016498e47e39e1e6"
+  integrity sha512-XtGIhXwF8YM8bJhGxG5kXgjkEuNGLTkoYqVE+KMR+aspr4KGYmKYg7yUe3KghyQ9yheNwLnjmzh/7+gfDBmHCQ==
 
-acorn@^6.1.1:
-  version "6.3.0"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.3.0.tgz#0087509119ffa4fc0a0041d1e93a417e68cb856e"
-  integrity sha512-/czfa8BwS88b9gWQVhc8eknunSA2DoJpJyTQkhheIf5E48u1N0R4q/YxxsAeqRrmK9TQ/uYfgLDfZo91UlANIA==
-
-acorn@^7.1.0:
-  version "7.1.0"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.1.0.tgz#949d36f2c292535da602283586c2477c57eb2d6c"
-  integrity sha512-kL5CuoXA/dgxlBbVrflsflzQ3PAas7RYZB52NOm/6839iVYJgKMJ3cQJD+t2i5+qFa8h3MDpEOJiS64E8JLnSQ==
-
-acorn@^7.1.1:
+acorn@^7.1.0, acorn@^7.1.1:
   version "7.4.0"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.4.0.tgz#e1ad486e6c54501634c6c397c5c121daa383607c"
   integrity sha512-+G7P8jJmCHr+S+cLfQxygbWhXy+8YTVGzAkpEbcLo2mLoL7tij/VG41QSHACSf5QgYRhMZYHuNc6drJaO0Da+w==