[TE-291] let travis use Java 8 to avoid running out of PermGen space
[TE-291] let travis use Java 8 to avoid running out of PermGen space

test-editor/test-editor-xtext,test-editor/test-editor-xtext,test-editor/test-editor-xtext,test-editor/test-editor-xtext,test-editor/test-editor-xtext