Add snippet for keyword completion?

[roxma]

ncm2/ncm2-snipmate#2 (comment)

// cc @wangsongiam

I assume that it is possible to identify the keyword completion return from jedi

It seems usefule. for some keyword based snippet, e.g. for loop

[casprwang]

tbh, I personally don't like snipping basic keyword-based syntax, especially with those multi placement snippet(I found it hard to use in Vim). In most of the cases, I would like to type myself.