Upgrade Travis build Maven to 3.5.0.
Upgrade Travis build Maven to 3.5.0.

Signed-off-by: Nikhil Nanivadekar <2a83e23f37e1f943921953c3c972d58ed41cfc08@gs.com>

bhav0904/eclipse-collections,bhav0904/eclipse-collections,bhav0904/eclipse-collections