0.4.0

What's Changed

• Create tokens module, make conda optional by @mcg1969 in #16
• Eliminate the uuid4 dependency by @mcg1969 in #18
• Add unit tests. by @jezdez in #15
• Patch cleanup by @mcg1969 in #19
• Preserve version token by @mcg1969 in #17
• Fix interrupted creation issue by @mcg1969 in #22
• Multithreading fixes by @mcg1969 in #20
• Add child environments to integration tests by @mcg1969 in #23

Full Changelog: 0.3.0...0.4.0