Issue/10 Fix get_media

[ilp416]

Closes #10

[genericlady]

@ilp416 I pulled in your branch and am getting

[1] pry(main)> RubyInstagramScraper.get_user_media_nodes( "gopro", "1259825963188747360" )
OpenURI::HTTPError: 404 Not Found
from /Users/yianna/.rvm/rubies/ruby-2.4.3/lib/ruby/2.4.0/open-uri.rb:363:in `open_http'
[2] pry(main)> RubyInstagramScraper.get_user_media_nodes( "gopro" )
OpenURI::HTTPError: 404 Not Found