Removes oraclejdk7 from Travis since it is not supported.
Removes oraclejdk7 from Travis since it is not supported.

Message from development list.

oraclejdk7 is not supported on Trusty image.
https://github.com/travis-ci/travis-ci/issues/7884

In the core, I just specified the old Precise image as a temporary
workaround.
https://github.com/mybatis/mybatis-3/commit/5f787f11a9cd61c8f861d3af7147628110f24dc0

...but I think it's OK to remove oraclejdk7 from the target JDK list
(openjdk7 works fine on Trusty).
mybatis/guice,hazendaz/guice