Ability to disable SSL cert verification

Adds a --no-ssl-verify argument.
Adds a no_ssl_verify boolean config option.

tests/samples/configs/has_everything.cfg

@@ -12,6 +12,7 @@ include =
     .*
 offline = false
 proxy = https://user:pass@localhost:8080
+no_ssl_verify = false
 timeout = abc
 api_url = https://localhost:0/api/v1/heartbeats
 hostname = fromcfgfile