v0.5.21 add email variable support

Added Email Variable support: get_email_variables and update_email_variable

v0.5.20 add get_email_template_used_by and update push_lead

Thanks to @petrklus for contributing a method for get_email_template_used_by .
Thanks to @suhaibwangdemck for fixing push_lead (made lookupField optional)

v0.5.19 add missing Smart Campaign methods

added methods for 'get smart campaign by name' and 'create/update/clone/delete smart campaign'

v0.5.18 Bug Fix for listing all Bulk Export Jobs

Previously, at most 300 Bulk Export Jobs were exported. Now it will take the nextPageToken and loop to download all Bulk Export Jobs for the past 7 days.

v0.5.17 Bug fix for "Get Smart Campaigns by Lead ID"

"Get Smart Campaigns by Lead ID" will now download more than 300 Smart Campaigns if the Lead is a member of over 300 Smart Campaigns. Also, the batchSize, earliestUpdatedAt and latestUpdatedAt are now implemented.

v0.5.16 timeout support by ViMonks; new method "Get Smart Campaigns by Lead ID"

Requests timeout support by @ViMonks ;
New method "Get Smart Campaigns by Lead ID"

v0.5.15 Stream Bulk files and Yield Folders and Lists

Changes:

• Stream Bulk files for the Bulk Extract API (contrib by @tkachoff)
• Made the error for reaching the daily bulk quota a fatal error rather than retrying (contrib by @java8964)
• Yield Folders and Lists rather than wait for all of them to download
• Fixed some readme typos

v0.5.14 Bulk Export Custom Objects and Program Members

Added support for bulk export for Custom Objects and Program Members.

v0.5.13 Submit Form

Added the Submit Form method

v0.5.12 Bug fix

v0.5.12 bug fix to handle 601 and 602 errors when passing in Access T…