Revert "BottleLoader: Use the formula stored in the bottle"

[ilovezfs]

Reverts #3176

[ilovezfs]

This has broken CI for python3.

==> brew install ./python3-3.6.2.high_sierra.bottle.1.tar.gz
==> FAILED
==> Installing dependencies for python3: pkg-config
==> Installing python3 dependency: pkg-config
==> Downloading https://homebrew.bintray.com/bottles/pkg-config-0.29.2.high_sierra.bottle.tar.gz
Already downloaded: /Users/brew/Library/Caches/Homebrew/pkg-config-0.29.2.high_sierra.bottle.tar.gz
==> Pouring pkg-config-0.29.2.high_sierra.bottle.tar.gz
/usr/local/Cellar/pkg-config/0.29.2: 11 files, 627.3KB
==> Installing python3
Warning: Building python3 from source:
  The bottle needs a /usr/local/Cellar Cellar (yours is /usr/local/Cellar).
==> Downloading https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz
Already downloaded: /Users/brew/Library/Caches/Homebrew/python3-3.6.2.tar.xz
Error: inreplace failed
setup.py:
  expected replacement of "@@HOMEBREW_PREFIX@@/ssl" with #<Pathname:/usr/local/opt/openssl>
==> brew test python3 --verbose
==> FAILED
Error: Testing requires the latest version of python3

https://jenkins.brew.sh/job/Homebrew%20Core%20Pull%20Requests/9849/version=high_sierra/console

[ilovezfs]

CC @sjackman @MikeMcQuaid

[sjackman]

Here's a fix #3250