Here you can find resources to setup your machine as a developer.
On OSX, first, you need to accept the developer licence, to do that launch Xcode and follow the process.
Next, fire up your favorite terminal and install:
Your git commit must starts with:
[+]
when you add something new, for example:[+] Use the new stripe api
[*]
when you update something, for example:[*] Update workding on renewal emails
[-]
when you fix something, for example:[-] Fix renewal emails