This is the same change as https://github.com/popomore/koa-proxy/pull/16, except I renamed the option to be yieldNext instead of yield_next to be consistent with the other options, and I added a test.
Coverage increased (+0.1%) to 96.875% when pulling 5d7f87ccd988e050b6352d7f29591682495f27d3 on GoBoundless:yieldNext into 848f3ef813681cd358a3e574c09a505d6baee3b4 on popomore:master.
This is the same change as https://github.com/popomore/koa-proxy/pull/16, except I renamed the option to be yieldNext instead of yield_next to be consistent with the other options, and I added a test.