Swapping out haystack for pyes.
Cribbing mapping from haystack.
Forcing all terms to be found.
Adding six requirement.
Merge branch 'search'

* search:
  Adding six requirement.
  Forcing all terms to be found.
  Cribbing mapping from haystack.
  Swapping out haystack for pyes.
Fixing two bugs: dont clear mapping/index when re-indexing at offset. Pull on pip upgrades.