Incremental Release

Changes:

• Close all Pub/Sub channels on connection close (see #88);
• Add iter() method to aioredis.Channel allowing to use it
  with async for (see #89);
• Inline code samples in docs made runnable and downloadable (see #92);
• Python 3.5 examples converted to use async/await syntax (see #93);
• Fix Multi/Exec to honor encoding parameter (see #94 and #97);
• Add debug message in create_connection (see #90);
• Replace asyncio.async calls with wrapper that respects asyncio version (see #101);
• Use NODELAY option for TCP sockets (see #105);
• New aioredis.ConnectionClosedError exception added. Raised if connection to Redis server is lost (see #108 and #109);
• Fix RedisPool to close and drop connection in subscribe mode on release;
• Fix aioredis.util.decode to recursively decode list responses;
• More examples added and docs updated;
• Add google groups link to README;
• Bump year in LICENSE and docs;