Update examples so they run with copy/paste

[karthik]

When people visit a tutorial and want to learn a new package, their first instinct is to copy paste example code and see how it works. We should strive to make that as easy as possible and not throw up errors when they do try. Looking at this gistr example:

gists(what = "minepublic")[[1]] %>% # List my public gists, and index 1st
  add_files("~/alm_othersources.md") %>% # Add new file to that gist
  update() # update sends a PATCH command to Gists API to add file to your gist

Users are unlikely to have a file locally called alm_sources.md. Could we update such examples to fully run as is?

e..g.

writeLines("test", con = file("alm_othersources.md"))
...

[sckott]

i updated those examples