[LIVY-390] Update travis to support JDK8 when building Livy against Spark 2.2

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.4.0
• Fix Version/s: 0.4.0
• Component/s: Tests
• Assignee: Saisai Shao
• Reporter: Saisai Shao
• Created: 03/Aug/17 02:30
• Updated: 03/Aug/17 03:24
• Resolved: 03/Aug/17 03:24

Description

Because Spark 2.2 removes JDK7 support but Livy still supports JDK7, so updating travis file to use JDK8 to build against Spark 2.2, whereas still using JDK7 to build with Spark 2.2-.