Code Refresh for python 312

A number of small fixes to allow pykep V2 be deployed on the conda system and work with py=>312.
This should be the last release before the V3 comes out and makes everything obsolete. Previous small release missed a PR merge.

Code Refresh for python 312

A number of small fixes to allow pykep V2 be deployed on the conda system and work with py=>312.
This should be the last release before the V3 comes out and makes everything obsolete.

Code Refresh

A code basis refresh with new CI, allowing to target releases for the new mac architecture (arm).

Optimize

This release contains the modifications that were deemed necessary to integrate pykep into the ESA "Optimize" platform!
We also thank @pabloem for adding linting to the CI thus catching early on possible python issues.

Fix for win compilers

As revealed by conda's toolchsin, the cspice code definition of the complex type is in conflict with win compiler. This point release fixes the issue changing that name to complex_type.

Spice Update

• The new cSPICE version is N0066, released April 10, 2017 from JPL.
• Several small bug fixes. All jupyter notebooks now run.
• Doc improvements

The Gym and More

In this release we have heavily reworked the build system as well as introduced a few interesting features, namely:

1 - A more, consolidated, prototype for the interplanetary trajectory gym.
2 - The possibility to compute complex gravity accelerations (due to high order harmonics).

Docs have been improved, but that is an area were more

Bug fixes and more support on Equinoctial Elements

This release includes general bug fixes and improvements. In particular equinoctial elements conventions are changed and TLE reads are now compatible with py27-37.

Python 37

In this release:

New Features

• The start of the open traj gym project. First few problems are added
• Build system Update
• Python 37 binaries

Bug FIxes

• Update to pygmo 2.7 so that examples work (#73 )

pykep 2.1. Some small bug fixes

• Bug fix in equinoctial elements
• New build system