--prefer-binary is an iffy option in the requirements file. It isn't
supported by some versions of pip, so I removed it from
requirements-base.txt and inserted it into the manual install
instructions where it seems to do what it is supposed to.
- This is only a test!
- The various environment*.yml and requirements*.txt files have all
been moved into a directory named "environments-and-requirements".
- The idea is to clean up our root directory so that the github home
page is tidy.
- The manual install instructions will start with the instructions to
create a symbolic link from environment.yml to the appropriate file
for OS and GPU.
- The 1-click installers have been updated to accommodate this change.
