v1.2.0

Added

• Citation information in the README file (see PR #472).
• Contribution guide on the project's wiki (https://github.com/ExoCTK/exoctk/wiki/Git-Workflow).
• Procedures for ExoCTK release (https://github.com/ExoCTK/exoctk/wiki/Release-Procedure).
• Support for installation via PyPI (see PR #385).
• JWST instrument throughputs for limb-darkening calculations (see PR #458).

Fixed

• Dropped support for python3.6 (see PR #471).
• Installation problem with Python 3.8 (see issue #465 and PR #469).
• Pip & asteval enviornment issues (see PR #468).

Changed

• Missing links to JDox on contamination tool (see PR #433).
• ExoCTK data is now downloaded as-needed for individual tools (see PR #488).