This is related to elastic/x-pack-elasticsearch#3877. This commit adds a route /start_basic that
will self generate a basic license. The only validation that is
performed is to check that you do not already have a basic license
installed. Additionally, if you lose features from switching to a basic
license, you must acknowledge the changes.
Original commit: elastic/x-pack-elasticsearch@7b8eeb50b1
Tim Brooks
Lisa Cawley