v1.3.0

Changes:

• Add 1.9.1, 1.9.0, and 1.8.9 to known versions (for DCOS_VERSION)
• Default to DC/OS 1.9.1
• Update default dcos-vagrant-box version to 0.9.2
• Disable vagrant halt with explanation and alternative
• Ban Vagrant 1.9.4 on Windows (no retry bug)
• Add vagrant install script for debian/ubuntu: ci/vagrant/install-latest-deb.sh
• Add integration tests to e2e suite
• Add VagrantConfig-1m-2a-1p.yaml for integration network tests
• Update CLI install script to support dev DC/OS versions
• Update postflight to support DC/OS 1.10 (3dt renamed to docs-diagnostics)