Upgrade to Node 12 LTS (#2831)

* Upgrade to node 12 LTS

* Run prettier

plugins/gatsby-source-react-error-codes/gatsby-node.js

@@ -20,9 +20,7 @@ exports.sourceNodes = async ({actions}) => {
     });
   } catch (error) {
     console.error(
-      `The gatsby-source-react-error-codes plugin has failed:\n${
-        error.message
-      }`,
+      `The gatsby-source-react-error-codes plugin has failed:\n${error.message}`,
     );
 
     process.exit(1);

plugins/gatsby-transformer-versions-yaml/gatsby-node.js

@@ -20,10 +20,12 @@ exports.onPostBuild = async ({store}) => {
 
   // versions.yml structure is [{path: string, url: string, ...}, ...]
   createRedirects(
-    versions.filter(version => version.path && version.url).map(version => ({
-      fromPath: version.path,
-      toPath: version.url,
-    })),
+    versions
+      .filter(version => version.path && version.url)
+      .map(version => ({
+        fromPath: version.path,
+        toPath: version.url,
+      })),
     redirectsFilePath,
   );
 };