如何使用brew安装特定版本flow

$ brew -v
Homebrew 1.2.0
$ flow version
Flow, a static type checker for JavaScript, version 0.45.0
$ flow
Launching Flow server for /Users/real/Desktop/reactPro/pro2
Wrong version of Flow. The config specifies version ^0.42.0 but this is version 0.45.0

[version]
^0.42.0

Warning: homebrew/versions was deprecated. This tap is now empty as all its formulae were migrated.

$ brew install flow
==> Downloading https://homebrew.bintray.com/bottles/flow-0.45.0.sierra.bottle.tar.gz
Already downloaded: /Users/real/Library/Caches/Homebrew/flow-0.45.0.sierra.bottle.tar.gz
==> Pouring flow-0.45.0.sierra.bottle.tar.gz
==> Caveats
Bash completion has been installed to:
 /usr/local/etc/bash_completion.d
zsh completions have been installed to:
 /usr/local/share/zsh/site-functions
==> Summary
�� /usr/local/Cellar/flow/0.45.0: 8 files, 6.4MB

https://homebrew.bintray.com/bottles/flow-0.42.0.sierra.bottle.tar.gz

/usr/local/Cellar/flow/

$ brew switch flow 0.42.0