Merge pull request #1 from jaynel/master

Initial source code and travis commit
Merge pull request #2 from jaynel/master

Create a queue of cassandra connections
Merge pull request #3 from jaynel/master

Add edocs
Merge pull request #4 from jaynel/master

Change elysium_connection:checkin/1 to return {Success, Available_Cxn_Count}
Merge pull request #5 from jaynel/master

Move checkin/checkout to elysium_queue; avoid serialized calls to get queue name
Improve error when cannot connect to cassandra