Add basic get methods and tests.
Implement utility methods get_campaign_list and get_campaign_detail.
Add cpc, cpm, ctr fields to the demographic data.
Add cost_per_total_action field in campaign detail demo data.
Add more data columns to the placement data.
Add support for keyword stats.
Fix a bug where access_token was overwritten for debug_token method.
Implement get_user_pages, get_page_access_token, create_link_page_post methods.
Bump up the version.
Make the optional arguments in the link page post optional.
Add offsite pixel creation method.
Change get_user_pages to take fields argument.
Add preliminary support for adcampaign, adcreative, adgroup creation.