Persist Queue Versions Save

Major change:

• [GH-49]SQLiteAckQueue: A simple and lightweight queue supporting "ack" based on sqlite queue.

Enhancements:

[GH-45]Use the highest protocol version for pickle

Features: [GH-39] Unique items only (no duplicates)

Enhancements: [GH-42] Use circle 2.0 for CI [GH-43 ]Add doc and tests for UniqueQ

Fixes: [GH-34]: Feature request: peek head item [GH-36]: task_done not behaving as I would expect

Fix:

• [GH-29]Fix cpu bound when queue is empty

Enhancement:

[GH-28]Speed up sqlite queue using WAL

Bugfixes: [GH-22]: In-Memory Database Issues [GH-24]: FIFOSQLiteQueue: the get() method returns None instead of blocking, and if I specify get(block=True) it raises the empty exception

Release v0.3.0 updates

Enhancements:

• [GH-21]Performance optimization for sqlite3 based queue
• [GH-18]Prefer sqlite3 queue over the file queue

Bug fixes:

• [GH-19]Make sure thread-safe for get of sqlqueue