Fixed make errors on a Ubuntu VM
Excluded . and .. to prevent rm from saying
rm: cannot remove directory: ‘public/.’
rm: cannot remove directory: ‘public/..’
Merge pull request #65 from concord-consortium/ubuntu-vm-buildfix

Fixed make errors on a Ubuntu VM
Fixed recently broken gradient code
It turned out that "repeat" was already a property of String.
I renamed some variables and did minor cleanup.