Tenable.io support (#70)

* Basic tenable.io support

* Add tenable config section

* Use existing variable

* Fix indent

* Fix paren

* Use ternary syntax

* Update Logstash config for tenable.io

configs/frameworks_example.ini

@@ -9,6 +9,17 @@ db_path=/opt/vulnwhisperer/database
 trash=false
 verbose=true
 
+[tenable]
+enabled=true
+hostname=cloud.tenable.com
+port=443
+username=tenable.io_username
+password=tenable.io_password
+write_path=/opt/vulnwhisperer/tenable/
+db_path=/opt/vulnwhisperer/database
+trash=false
+verbose=true
+
 [qualys]
 #Reference https://www.qualys.com/docs/qualys-was-api-user-guide.pdf to find your API
 enabled = true