Switch Git Push Default

Switching to Git Push Default to use simple:

“git config --global push.default tracking” has been deprecated in
recent versions of git and it’s now an alias for ‘upstream’.  The new
“safer” default is ‘simple’ which is like ‘upstream’ (formerly
‘tracking’), except that it refuses to push to an upstream branch which
is named differently than the local branch.

http://git-scm.com/docs/git-config