Pass in refence for convert. Fixes #54
Pass in refence for convert. Fixes #54

As written in https://github.com/travs/markdown-pdf/issues/54 and the comments of https://github.com/travs/markdown-pdf/commit/4dd21b379bee37da0e2e696739883452d79c9141

convert() caused an error in Atom. Without the braces it work.
NKMR6194/markdown-pdf,travs/markdown-pdf,travs/markdown-html