Updated shodan_search for new API
Committing changes from r7 comments
Addressed r7 comments, fixed bug in results loop
Fix windows cmd redirection in ff payloads.
Quick fix for ssh_login_pubkey

Fixes #3772, closes #3774
Land #3775 - ssh_login_pubkey fix for the uninit prepended_creds bug

Closes #3774
Add conditions to check healthy shodan results
Land #3677 - Updated shodan_search for new API
Land #3773 - Fix windows cmd redirection in firefox payloads
Update CONTRIBUTING.md

Redmine is on its way out. See here: 

https://github.com/rapid7/metasploit-framework/wiki/Decommissioning-Redmine
Update CONTRIBUTING.md

Fix a sentence.
Land @todb-r7's #3776, s/redmine/github issues/g