Remove auth/security from TODO in README
Getting started guide.

How to:
 1. Setup a cluster and get a session
 2. Execute queries on that session (with block and async calls)
 3. Understanding how session's execute a query with a load balancing policy
Merge pull request #72 from riltsken/adding_a_getting_started_guide

Getting started guide.
Installation, more complete Getting Started guide
Update link to docs in README
Generators map to list collections, not sequences
Update unit test for generator change
Reconnect after failed node up under all conditions
Fix bad log statement
Avoid race condition when adding new host

If the futures completed before the original loop did,
we would run _finalize_add twice
Don't reference uninitialized conn in finally block

If we failed to get a connection, the finally block
would try to reference an uninitialized variable
Log unhandled exceptions in scheduled tasks
Check that conn is not None before closing
Ensure reconnector is started on failed node add

Because the node was still marked down, the reconnector
would not be started when we failed to add a connection pool for a
recently added node.
Increase delay before connecting to new nodes
doc changes
Minor doc tweaks
Add requirements.txt
Add test-requirements.txt
Remove versions from requirements.txt