EPS files not created

[russtoku]

When I add EPS file creation to the example usage program on the README.md page, I get errors like this:

ERROR: could not create EPS file for: usage_example, switch | exit status 1

I added this line to the example usage program before the cad.Draw() line:

cad.Result.Formats = append(cad.Result.Formats, []string{"eps"}...)