Version 1.7.0-RC1
R20 compat for 1.x.x (#952)

* enable R20 builds

* s/crypto:rand_bytes/crypto:strong_rand_bytes/

* R20 compat

* add couch_rand to build chain

* add R20 to travis tests

* add couch_rand module, nicked from #860

* support R15 and R16

* fix attachment tests for r20, backport of #874

* drop R14 from travis

* update to latest erlang versions
23 files changed