rtweet: post_follow function returns read only error

Question

I recently implemented the rtweet package to begin pulling and posting Twitter data. The get_ family of functions work fine but when I run a post_ function, in this case post_follow, I get a read-only error. See below:

 > rtweet::post_follow(user = 'hadleywickham')
 $request
 [1] "/1.1/friendships/create.json"

 $error
 [1] "Read-only application cannot POST."

I checked to make sure my tweets are not protected.