Release master HEAD on hackage

[naushadh]

I see build failures that could be preventing this, however I'm unable to build 0.3.0.1 in LTS-10.7 ( duplicate Binary instances error for Text).

Pinning stack to master/head solves the build issues.

[naushadh]

Dug deeper into the code and realized the master branch is in the middle of some deep refactoring to introduce file system persistence of the search index; as such, this is not representative at all of the version available on hackage.

But I was interested in using hunt-searchengine with the latest/greatest LTS-11 stackage resolver without carrying the baggage of a partial refactor feature that isn't even being fully used. So

• I've picked a point in code right before the introduction of SegmentIndex, but after the addition of several minor fixes.
• Patched it to work with the latest resolver

Here is my branch that is hunt-searchengine with resolver 11 compatibility: https://github.com/naushadh/hunt/tree/pre-segment-index

Would be happy to open a PR with my branch so we can hopefully get an official release with latest stackage compatibility and move the current SegmentIndex refactoring to an isolated branch.