travis: add missing libs: xdamage + xfixes

> configure: error: Package requirements (x11 xext xdamage >= 1.1 xfixes
> x11-xcb xcb xcb-glx >= 1.8.1 xcb-dri2 >= 1.8) were not met:
> No package 'xdamage' found
> No package 'xfixes' found

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
1 file changed