fix(deps): update dependency prop-types to v15.7.0

Author: renovate-bot

site/package.json

@@ -27,7 +27,7 @@
     "gatsby-transformer-remark": "2.2.4",
     "node-sass": "4.11.0",
     "prismjs": "1.15.0",
-    "prop-types": "15.6.2",
+    "prop-types": "15.7.0",
     "react": "16.8.1",
     "react-dom": "16.8.1",
     "react-helmet": "5.2.0",

site/yarn.lock

@@ -10880,7 +10880,15 @@ promise@^7.1.1:
   dependencies:
     asap "~2.0.3"
 
-prop-types@15.6.2, prop-types@^15.5.4, prop-types@^15.6.1, prop-types@^15.6.2:
+prop-types@15.7.0:
+  version "15.7.0"
+  resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.7.0.tgz#cc45233a8ccef80f4a2e3a6bf575bee4e19b4a50"
+  integrity sha512-rlfizAIb1WrkMkbFm3uk7cZGqeVPOhHHMj3gy9FUHE+Ha5lKvbIzj9ygvLdG8Cv2CQEhQnP5djXS7pbmTOpBqw==
+  dependencies:
+    object-assign "^4.1.1"
+    react-is "^16.8.1"
+
+prop-types@^15.5.4, prop-types@^15.6.1, prop-types@^15.6.2:
   version "15.6.2"
   resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.6.2.tgz#05d5ca77b4453e985d60fc7ff8c859094a497102"
   integrity sha512-3pboPvLiWD7dkI3qf3KbUe6hKFKa52w+AE0VCqECtf+QHAKgOL37tTaNCnuX1nAAQ4ZhyP+kYVKf8rLmJ/feDQ==
@@ -11162,6 +11170,11 @@ react-hot-loader@^4.6.2:
     shallowequal "^1.0.2"
     source-map "^0.7.3"
 
+react-is@^16.8.1:
+  version "16.8.1"
+  resolved "https://registry.yarnpkg.com/react-is/-/react-is-16.8.1.tgz#a80141e246eb894824fb4f2901c0c50ef31d4cdb"
+  integrity sha512-ioMCzVDWvCvKD8eeT+iukyWrBGrA3DiFYkXfBsVYIRdaREZuBjENG+KjrikavCLasozqRWTwFUagU/O4vPpRMA==
+
 react-lifecycles-compat@^3.0.4:
   version "3.0.4"
   resolved "https://registry.yarnpkg.com/react-lifecycles-compat/-/react-lifecycles-compat-3.0.4.tgz#4f1a273afdfc8f3488a8c516bfda78f872352362"