Let Travis run all examples
Escape dollar-sign in makefile
Add matplotlib to Travis dependencies
Set matplotlib backend to Agg
Use current matplotlib version Python 3
Escape greather-than symbol
Escape double-colon symbol
Change python version test
Fix wrong escaping
Add missing python version to pip
Remove escaping
Change invalid install order
Move example runner loop to Travis config
Unescape dollar sign
Add better description for example runner
Fix print statement for Python 3
Add missing future import