ssh_scan v0.0.9 release

• Fix Ubuntu OS fingerprint typo (#60)
• Fix hard failure in host-key fingerprinting (#67, #81, #83)
  • Special thanks to @jvehent
• Fix typos/bugs in README (#72, #82, #90)
  • Special thanks to @knweiss
• Fix net-ssh port specification bug (#73)
  • Special thanks to @comfreak
• Fix spacing in recommendations output (#70)
  • Special thanks to @anantshri
• Improvements to source installation documentation (#80)
  • Special thanks to @pjackowski
• Add unit-test for ssh_scan versioning (#62)
• Add RedHat/Windows OS fingerprints (#63)
• Add 2.2.0 and 2.3.0 Rubies to CI builds (#68, #75)
• Add preliminary support for multi-ip scanning (#65, #69, #76)
  • Special thanks to @jinankjain
• Add docker build process for travis-ci (#85, #88)
  • Special thanks to @jvehent

Gem release: https://rubygems.org/gems/ssh_scan/versions/0.0.9