fix(gatsby-ssr): fixes missing key warning in react (#6)

Adds missing key property to link in gatsby-ssr.js#onRenderBody -> setHeadComponents method

Author: weirdpattern

.npmignore

@@ -2,4 +2,5 @@
 !gatsby-ssr.js
 !index.js
 !package.json
-!README.md
+!README.md
+!LICENSE

.npmrc

@@ -0,0 +1 @@
+package-lock = false

package.json

@@ -26,8 +26,8 @@
     "plugin"
   ],
   "scripts": {
-    "build": "cross-env BABEL_ENV=production babel src --out-dir .",
-    "clean": "rimraf ./node_modules",
+    "build": "rimraf gatsby-ssr.js index.js && cross-env BABEL_ENV=production babel src --out-dir .",
+    "clean": "npx rimraf node_modules",
     "format": "prettier --write ./{src,specs}/{,**}/*.js",
     "lint": "eslint ./{src,specs}/{,**}/*.js",
     "test": "jest",
@@ -46,9 +46,9 @@
     "cross-env": "^5.2.0",
     "eslint": "^5.9.0",
     "eslint-config-prettier": "^3.3.0",
+    "eslint-plugin-filenames": "^1.3.2",
     "eslint-plugin-jest": "^22.1.1",
     "eslint-plugin-json": "^1.3.2",
-    "eslint-plugin-filenames": "^1.3.2",
     "eslint-plugin-prettier": "^3.0.0",
     "husky": "^1.2.0",
     "jest": "^23.6.0",

src/gatsby-ssr.js

@@ -16,6 +16,7 @@ export function onRenderBody({ setHeadComponents }, options = {}) {
   if (options.includeDefaultCss !== false) {
     return setHeadComponents([
       <link
+        key="gist-embeded-87673c31a5b37b5e6556b63e1081ebbc"
         rel="stylesheet"
         href="https://assets-cdn.github.com/assets/gist-embed-87673c31a5b37b5e6556b63e1081ebbc.css"
       />