new 0.3.0 release with zenodo

[orbeckst]

Cut a 0.3.0 release.

Include

• new IMDv2 support IMDv2 support and tests for receiving positions #140
• PyPi package
• zenodo archive copy (need to create a release, check https://zenodo.org/account/settings/github/repository/Becksteinlab/imdclient)

[orbeckst]

For the other minor things we can do a quick 0.2.4 #146