Bump acorn from 6.2.0 to 6.4.1 (#73)

Bumps [acorn](https://github.com/acornjs/acorn) from 6.2.0 to 6.4.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](acornjs/acorn@6.2.0...6.4.1)

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Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

yarn.lock

@@ -255,8 +255,8 @@ acorn-dynamic-import@^4.0.0:
   resolved "https://registry.yarnpkg.com/acorn-dynamic-import/-/acorn-dynamic-import-4.0.0.tgz#482210140582a36b83c3e342e1cfebcaa9240948"
 
 acorn@^6.0.5:
-  version "6.2.0"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.2.0.tgz#67f0da2fc339d6cfb5d6fb244fd449f33cd8bbe3"
+  version "6.4.1"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.1.tgz#531e58ba3f51b9dacb9a6646ca4debf5b14ca474"
 
 adm-zip@^0.4.7:
   version "0.4.7"