send back event with substituted command tokens
Updating check validation for unpublished checks.

Unpublished checks (configured with the 'publish' attribute
as false) are not scheduled to run on any interval.  Hence,
these checks do not require a valid interval to run.  This
change updates the check validation to take this into consideration.
Merge pull request #532 from nstielau/unpublished_check_validation

Updating check validation for unpublished checks.
[535] fix stale client detection w/ in progress client deletions
Merge pull request #536 from portertech/535

Fix stale client detection w/ in progress client deletions (#535)
[534] check name cannot contain spaces or special characters
Merge pull request #537 from portertech/534

Check name cannot contain spaces or special characters (#534)
[payloads] moved invalid result log line to valid_result?()
Merge pull request #538 from portertech/payloads

[payloads] moved invalid result log line to valid_result?()
[token_default] reduce the number of ternary operators in token substitution
Merge pull request #539 from portertech/token_default

[token_default] reduce the number of ternary operators in token substitution
Merge pull request #525 from piavlo/feature/return-result-with-substituted-command-tokens

send back event with substituted command tokens
[525] command_executed, command after token substitution
Merge pull request #540 from portertech/525

[525] command_executed, command after token substitution
beta version bump, 0.9.13.beta.1
version bump, 0.9.13, updated the changelog