Missing Dosis font for image test

[archmoj]

We used to get Dosis from the address below for the image test.
https://github.com/eliheuer/dosis-vf/blob/master/fonts/static-fonts/

But it is now missing causing these baselines to fail:
gl3d_indicator_scatter3d,
indicator_bignumber,
indicator_scatter

[alexcjohnson]

Let's just take Dosis out. There's nothing special about it, we have plenty of other fonts represented in our tests.

[archmoj]

Side effect of googlefonts/dosis-vf#15