Add badges, History.md and Releasing.md (#23)

Releasing.md

@@ -0,0 +1,21 @@
+# HTTPure Releasing Guide 
+
+1. Check out the branch you will be releasing (generally `master`, but sometimes
+   an older release series branch). Ensure all relevant commits and PRs have
+   been merged.
+2. Update [History.md](History.md) by changing "unreleased" to the new
+   version/date.  Example diff:
+```diff
+-unreleased
+-==========
++1.0.0 / 2017-07-10
++==================
+```
+3. Commit your update to [History.md](History.md). Use the message "Release
+   notes for v<new version number>".
+4. Run `pulp version` in the project root. This will check the project for any
+   issues and create a new version tag and empty checkpoint commit.
+5. Push the release notes and version commit and version tag.
+6. If you are pushing a non-patch release, create and push a branch named with
+   the version series, i.e. `v0.1.x`.
+7. [Create the release on github](https://github.com/cprussin/purescript-httpure/releases/new).