update master branch into your branch code example

Example 1: git update branch from master

git checkout test-branch 	//Checkout the branch you want to update
git merge master			//Merge all code from master to test-branch

// When your are done with test-branch you can merge all code into master branch
git checkout master 		// Make sure you are on master branch
git merge test-branch

Example 2: update branch with master

MERGE METHOD: (keeps branch history accurate)
git checkout b1
git merge origin/master
git push origin b1

REBASE METHOD: (history will appear linear, will conflict if already pushed)
git checkout b1
git rebase master