update fork repository

Shell
git fetch upstream

git checkout master

git merge upstream/master

git push origin## Add Original Repository
git remote add upstream https://github.com/OriginalOwner/OriginalProject.git

## Verify if Repository is added
git remote -v

## Fetch Updates from Original Repository
git fetch upstream

## Checkout to your master branch
git checkout master

## Get Updates from upstream repo
git merge upstream/master

## Push the commit over 
git push origin master
Source

Also in Shell: