Version 0.6.0

Minor version to sort out the (still circular) dependency to ScopeSim.

What's Changed

Dependency Changes

• Sync dependencies with ScopeSim 0.9.0 by @teutoburg in #107
• Fix and improve RTD page by @teutoburg in #108

Other Changes

• Fix pytest --doctest-modules by @hugobuddel in #105
• Fix and test calibration module by @hugobuddel in #104
• Add docstring tests to CI by @hugobuddel in #106

Full Changelog: v0.5.4...v0.6.0