BOUNDARY-1753 - fix deduplication criteria so it actually references a dynamic field

Test Plan: Tested against local Splunk installation

Reviewers: ray, philip

Differential Revision: http://phabricator.cid1.boundary.com/D990
Fixing message in saved-search alert command and execution on windows by removing shebang statement

Splunk 6.0.1 tries to parse the shebang and execute the script using the command specified, however /usr/bin/env doesn't exist on Windows so this fails. If the shebang is removed Splunk falls back to determining the environment to run based on the file extension. This fix doesn't work on Splunk 6.0.0 or older so I'm not keen on it but I can't see any other portable ways to fix this.
Removing eventKey field, updating sender type to be 'host' and simplifying createdAt date logic
Making boundary.py pep8 compliant
Fixing indent on create_event
Updating fingerprintFields based on feedback from Patrick
BOUNDARY-1753 - fix deduplication criteria so it actually references a dynamic field

Test Plan: Tested against local Splunk installation

Reviewers: ray, philip

Reviewed By: ray

Differential Revision: http://phabricator.cid1.boundary.com/D990