[FIRST] plotlyupdate.m

@chriddyp wanna look this over when you get a chance. 

plotlyupdate
plotlyupdate('verbose') 
ploltyupdate('verbose','nocheck') 
... because `setup.m` and `readme.md` are the two files at the root of the plotly repo? should we abstract this to just not copy *any* files at the root of the repo (so that if we add another file to the root, we don't have to hard-code in that file here)?