Bump to 1.5.0

The last few releases have introduced new features, primarily
Progressive Web App support, server-side rendering for content + shell
and so on. To reflect this in our versioning, doing a non-patch bump.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-hn",
-  "version": "1.4.13",
+  "version": "1.5.0",
   "description": "React-powered frontend for Hacker News using its Firebase API",
   "author": "Jonny Buchanan",
   "license": "MIT",