mendeley_conf: Create, Load and Save client_id and client_secret
In zeehio/mendeleyr: Mendeley API for R

Create, Load and Save client_id and client_secret

mdl_conf_new()

mdl_conf_save(client_id, client_secret, where = ".mendeley_conf.json")

mdl_conf_load(where = ".mendeley_conf.json", try_env = TRUE)

`client_id`	The client id given by Mendeley when you create an app at http://dev.mendeley.com/myapps.html
`client_secret`	The client secret given by Mendeley when you create an app
`where`	File name where mendeleyr will store the client_id and client_secret
`try_env`	Try loading parameters from OS environment variables `MENDELEY_CLIENT_ID` and `MENDELEY_CLIENT_SECRET`