HumanTaskAgent can now accept `combination_mode` and `poll_options` which are used to generate a poll from the HITs answers.  The poll asks additional Mechanical Turk users to rate the responses, and then the best one is returned.  This allows for an additional step of validation on user generated content / data.
Merge branch 'master' into human_task_agent_makes_polls
doc
Merge pull request #114 from albertsun/event-email-agent

Event email agent
a webhook agent to create events from webhooks.
configurable webhook payload , update description, improve tests
add keep_events_for as an optional field for agents to decide how long to store events
cleanup failed delayed_jobs by default (for table speed)
in order to avoid leaking memory, remove all symbolization
switch from yaml to json serialization
globally avoid using symbols since we're moving to json storage
puts
fix spec typo
fix test logic :grin:
update dotenv-rails and attempt to make cap sync:db:down work with remote .env files
transform and clean utf-8
Only load the fields we need for the autocomplete.
add cached columns for event creation and last errors, reducing the number of SQL queries
fix spec?
typo