Fix location of .virtualenvs dir in macOS.md
Fix location of .virtualenvs dir in macOS.md

Previously, the documentation called for the user to set their dir for
virtualenvs to `~/virtualenvs` rather than `~/.virtualenvs`. This will
fix that typo.

Signed-off-by: Cullen Taylor <0a4f58109a9f9b7b2781cb48fa62bfe7918cb3d0@outlook.com>

BonnyCI/bonnyci.org,BonnyCI/bonnyci.org,BonnyCI/bonnyci.org,BonnyCI/bonnyci.org