Fixes SNI issues #57

[kleisauke]

This will fix issues with Server Name Indication (for example sites using the CloudFlare Flexible SSL service). With this pull request the error Caused by: javax.net.ssl.SSLException: Received fatal alert: internal_error for this URL: https://api.rocrooster.net/api-docs.json is gone.

The following things are updated:

• Maven WAR Plugin to 2.6
• Maven Failsafe Plugin to 2.19
• Jetty to 9.2.14.v20151106
• javax.servlet to 3.1.0
• Jackson Dataformat YAML to 2.6.4
• Jersey to 2.22.1
• Commons IO to 2.4

The following things are changed:

• Used Apache HttpClient instead of URLConnection

I hope you'll like it.