release 0.7.0

[orbeckst]

We have a complete 0.7.0 milestone and we have nothing that must be in 0.7.0 so I am just going to make a quick release.

(The 1.0 release #208 can then collect whatever else we deem necessary.)

Release management

• [x] updated CHANGES
• [x] tagged 0.7.0
• [x] checked testpypi version
• [x] created release on GitHub
• [x] created conda package (reviewed and merged the cf-regro commit to the conda-forge repo for the conda package)
• [x] announced in forum

[orbeckst]

With PR https://github.com/conda-forge/alchemlyb-feedstock/pull/5 merged, all packages are up.

[orbeckst]

@IAlibay thank you for adding the deployment CI — made release A LOT easier.