Setting editorTheme property does not change theme

[grrttedwards]

For graphiql starter, according to the README, it's possible to set the editorTheme property to change the styles to a custom theme. Setting this theme seems to have no effect, it appears that a stylesheet must be linked in the generated html document, and this property does not do that.

See https://github.com/graphql/graphiql#applying-an-editor-theme

Related to #156

[oliemansm]

Fixed in next release, thanks for reporting.