Add -run-healthcheck option

Changelog for 0.7.3:

• PR #87 Add healthcheck subcommand. by @reitermarkus
• PR #88 Add .idea to the .gitignore file by @coolbeevip

Note: This change is only useful for exec healthchecks and not for http probes. Wherever possible users should only use http healthchecks since exec is very resource intensive.

Generated by Derek