[Request] Add option to specify user agent

[boxfriend]

With the bot generating a random user-agent instagram seems to detect it fairly quickly. However, by specifying the user-agent of the broswer i generally sign into the account with instagram does not detect the bot nearly as quickly, generally only if it runs for an extended period of time.

The only problem with this is whenever there is an update, the user-agent in the python file must be changed, so I'd like to request an option to specify it in the config instead.

[yurilaaziz]

in your configuration file just put the list of user agents

ie:

list_of_ua:
- "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0.6.01001)"