Maven error in OS X: “Maven already installed, it’s just not linked”

If you use Homebrew on OS X and you come across the error below, just:

1. $ rm -rf /usr/local/Cellar/maven
2. $ brew install maven
3. $ mvn -version
4. That’s it!

$ brew install maven
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 2 taps (caskroom/cask, caskroom/versions).

Warning: maven-3.5.0 already installed, it's just not linked.