Define an user main branch

[mdbs99]

Let's give a possibility to user could define its own main branch (default is master).
Sometimes we could not push our changes into the main branch because this could be dangerous. So, because that, the user could define its own main branch.

This parameter should be stored in .gitconfig file with an option to user choose globally or not.

This main branch will be used in done, push, and release commands.

[mdbs99]

It's better using git config instead create a new command.

So, these are the commands:

• set info: git config git-work."branch".master master
• get info: git config --get git-work.branch.master

This should be part of git-work.sh install as per #6.

[mdbs99]

Well, maybe we can give to users just a command to set the main branch when them want like this:
git work config branch.master mybranch

[fabriciofx]

@mdbs99 To fix this issue, I need you merge PR #3 first.

[mdbs99]

@fabriciofx don't worry about this issue. When PR #3 is merged, I may do this issue.
Please, give attention in #10.