travis: bump to oraclejdk8
travis: bump to oraclejdk8

oraclejdk7 is officially eol and not more supported. This is why the
build is failing. Similar issue can be found here:
https://github.com/OpenRefine/OpenRefine/issues/1223

deploy:
 * Add a new specific deploy section instead of wrapping up in
after_success hook.
 * It makes sense to only deploy artifacts from the release branch
(master).

Signed-off-by: Lionel H <94ac81d302bde621dbeb66cb17ee93dd423a8326@tessares.net>

segator/scaleway-sdk,segator/scaleway-sdk