Update gatsby monorepo

Author: renovate-bot

package.json

@@ -14,27 +14,27 @@
     "bulma": "0.8.0",
     "classnames": "2.2.6",
     "feed": "4.0.0",
-    "gatsby": "2.18.21",
+    "gatsby": "2.19.17",
     "gatsby-background-image": "0.9.11",
-    "gatsby-image": "2.2.38",
+    "gatsby-image": "2.2.41",
     "gatsby-plugin-alias-imports": "1.0.5",
-    "gatsby-plugin-catch-links": "2.1.24",
+    "gatsby-plugin-catch-links": "2.1.25",
     "gatsby-plugin-facebook-pixel": "1.0.3",
-    "gatsby-plugin-google-analytics": "2.1.32",
-    "gatsby-plugin-manifest": "2.2.37",
-    "gatsby-plugin-mdx": "1.0.67",
-    "gatsby-plugin-page-creator": "2.1.38",
-    "gatsby-plugin-react-helmet": "3.1.21",
+    "gatsby-plugin-google-analytics": "2.1.35",
+    "gatsby-plugin-manifest": "2.2.41",
+    "gatsby-plugin-mdx": "1.0.73",
+    "gatsby-plugin-page-creator": "2.1.40",
+    "gatsby-plugin-react-helmet": "3.1.22",
     "gatsby-plugin-robots-txt": "1.5.0",
-    "gatsby-plugin-sass": "2.1.27",
-    "gatsby-plugin-sharp": "2.3.13",
-    "gatsby-plugin-sitemap": "2.2.25",
-    "gatsby-remark-copy-linked-files": "2.1.36",
-    "gatsby-remark-images": "3.1.42",
-    "gatsby-source-contentful": "2.1.76",
-    "gatsby-source-filesystem": "2.1.46",
-    "gatsby-transformer-remark": "2.6.48",
-    "gatsby-transformer-sharp": "2.3.12",
+    "gatsby-plugin-sass": "2.1.28",
+    "gatsby-plugin-sharp": "2.4.5",
+    "gatsby-plugin-sitemap": "2.2.27",
+    "gatsby-remark-copy-linked-files": "2.1.37",
+    "gatsby-remark-images": "3.1.44",
+    "gatsby-source-contentful": "2.1.86",
+    "gatsby-source-filesystem": "2.1.48",
+    "gatsby-transformer-remark": "2.6.51",
+    "gatsby-transformer-sharp": "2.3.14",
     "immutability-helper": "3.0.1",
     "lodash": "4.17.15",
     "mdx-utils": "0.2.0",