ditch support for Elasticsearch 0.90

[willkg]

We can remove all support for anything in Elasticsearch 0.90 that isn't in Elasticsearch 1.0+.

This includes:

• updating the minimum required version of elasticsearch-py to 1.0
• removing the bulk indexing monkey patching code I added
• updating the documentation

Is there anything else that needs to be changed?

[adngdb]

@willkg What's the status here? It seems to me you already have done all of those bullet points. Is there something I can do to help in this process?

[willkg]

I inverted the bulk indexing monkey patching code so that it's monkey patching the other direction. It's still there.

We still have a bunch of stuff in there for supporting Elasticsearch 0.90 including in the docs.

Thus of the bullet points, the only one that's really done is the first one.