test(Visual regressions): Test that file can be got
test(Visual regressions): Test that file can be got

See discussion in #33: https://github.com/stencila/thema/issues/33#issuecomment-584593727

stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila