🚚 change pypi name to asbestos-snow

[itsthejoker]

Ticket: pypi/support#2621

Description:

The asbestos package name on PyPI is currently taken by someone with no packages published, so we've started the process of requesting the name for our use. However, this process can take a very long time -- >8-10 weeks. Since we want to start using this immediately, we've elected to do the following:

• rename the installer name of asbestos to asbestos-snow
• keep everything else the same (use with import asbestos, etc)
• wait until we hear movement on the name request
• if / when the name request goes through, we will:
  • move this package to asbestos
  • publish an alias package for 6 months to a year at asbestos-snow that simply installs the latest version of asbestos, à la django rest framework's redirect
  • remove the redirect package after enough time has passed

This PR just renames the install name to asbestos-snow and updates documentation related to installation.