Don't be so specific with versions in gemspec

Allow log_agent to run with minro gem upgrades for all gems.
Remove rabbitmq connection test

- Added to find cause of issues, does not actually test logagent code.
Fix tests for loading events minus captured and timestamp fields

- calling delete on a string not the hash, because parentheses in the
  wrong the place. Tests now correctly test loading a payload minus the
  specific fields.