1.2.0

Version 1.2.0 of AGNI has some significant improvements.
In summary:

• Supports real-gas equations of state (AQUA, Chabrier, Van der Waals)
• Improvement to hydrostatic integration (now uses RK4 integrator and supports self-gravity interactions)
• Updated the docs and generally tried to make things more accessible. This includes a src/get_agni.sh script which will update the code.
• Modularised the codebase significantly, especially in atmosphere.jl
• Added new tests

Pull requests

• Real gas equations of state by @nichollsh in #82
• H2 Chabrier EOS, Runge-Kutta hydrostatic integration, self-gravity by @nichollsh in #87
  Full Changelog: 1.0.0...1.2.0