Add gatsby v2 as peer dependencie

Author: Benjamin Abel

package.json

@@ -35,5 +35,8 @@
   },
   "dependencies": {
     "elasticlunr": "^0.9.5"
-  }
+  },
+  "peerDependencies": {
+    "gatsby": ">2.0.0-alpha"
+},
 }

src/gatsby-node.js

@@ -50,6 +50,7 @@ const createOrGetIndex = async (node, cache, getNode, server, {
 
     for (const pageId of node.pages) {
         const pageNode = getNode(pageId);
+
         const fieldResolvers = resolvers[pageNode.internal.type];
         if (fieldResolvers) {
             const doc = {
@@ -99,6 +100,7 @@ exports.sourceNodes = async ({ getNodes, actions }) => {
 exports.onCreateNode = ({node, actions, getNode}, {
     resolvers,
 }) => {
+  
     if (Object.keys(resolvers).indexOf(node.internal.type) === -1) {
         return;
     }