Major updates

• Added SSO support (OpenID Connect) for HTTP and SSH targets (#222)
• Added support for linking HTTP targets to subdomains
• HTTP: added support for tickets (as a GET parameter or Authorization header)

Changes

• HTTP: added X-Forwarded-* headers
• HTTP: session cookie is now set for all subdomains
• UI: added proper connection instructions for tickets
• UI: added test-target CLI support for HTTP and MySQL targets
• SSH: added support for AES-CTR ciphers, and diffie-hellman exchanges
• Sessions will be automatically killed if you revoke access by editing the config file
• Fixed scp not triggering target connection