diff --git a/yarn.lock b/yarn.lock
index f46c25c..543a9b9 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2012,7 +2012,7 @@ core-js@^1.0.0:
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-1.2.7.tgz#652294c14651db28fa93bd2d5ff2983a4f08c636"
   integrity sha1-ZSKUwUZR2yj6k70tX/KYOk8IxjY=
 
-core-js@^2.4.0, core-js@^2.5.3, core-js@^2.6.5:
+core-js@^2.4.0, core-js@^2.6.5:
   version "2.6.11"
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.11.tgz#38831469f9922bded8ee21c9dc46985e0399308c"
   integrity sha512-5wjnpaT/3dV+XB4borEsnAYQchn00XSgTAWKDkEqv+K8KevjbzmofK6hfJ9TZIlpj2N0xQpazy7PiRQiWHqzWg==
@@ -3570,15 +3570,6 @@ map-visit@^1.0.0:
   dependencies:
     object-visit "^1.0.0"
 
-markdown-navbar@^1.1.2:
-  version "1.1.2"
-  resolved "https://registry.yarnpkg.com/markdown-navbar/-/markdown-navbar-1.1.2.tgz#8d8fa0d7dce44e62695e627e3a2146c1b64dad60"
-  integrity sha512-A1ql1Eq86Jonl/4fXN5h3iP/RqnnG823GHDfKLX76SV76xZa5QmGYuGLx1r/yKe/JwscqzxUYTk5Qy++OqlT3g==
-  dependencies:
-    core-js "^2.5.3"
-    prop-types "^15.6.0"
-    react "^16.2.0"
-
 marked@^0.8.0:
   version "0.8.0"
   resolved "https://registry.yarnpkg.com/marked/-/marked-0.8.0.tgz#ec5c0c9b93878dc52dd54be8d0e524097bd81a99"
@@ -5417,7 +5408,7 @@ react-slick@~0.25.2:
     lodash.debounce "^4.0.8"
     resize-observer-polyfill "^1.5.0"
 
-react@16.12.0, react@^16.2.0:
+react@16.12.0:
   version "16.12.0"
   resolved "https://registry.yarnpkg.com/react/-/react-16.12.0.tgz#0c0a9c6a142429e3614834d5a778e18aa78a0b83"
   integrity sha512-fglqy3k5E+81pA8s+7K0/T3DBCF0ZDOher1elBFzF7O6arXJgzyu/FW+COxFvAWXJoJN9KIZbT2LXlukwphYTA==
@@ -6496,9 +6487,9 @@ xtend@^4.0.0, xtend@~4.0.1:
   integrity sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ==
 
 y18n@^4.0.0:
-  version "4.0.0"
-  resolved "https://registry.yarnpkg.com/y18n/-/y18n-4.0.0.tgz#95ef94f85ecc81d007c264e190a120f0a3c8566b"
-  integrity sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w==
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/y18n/-/y18n-4.0.1.tgz#8db2b83c31c5d75099bb890b23f3094891e247d4"
+  integrity sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ==
 
 yallist@^3.0.2:
   version "3.1.1"