BUILD: CI: comment out cygwin build, upgrade various ssl libraries

BUILD: CI: comment out cygwin build, upgrade various ssl libraries

cirrus ci builds are now limited to branches master, next
travis-ci images are upgraded to ubuntu bionic
cygwin builds are temporarily disabled on travis-ci
(maybe someone will figure out how to fix them, here's link
https://travis-ci.community/t/cygwin-issue-cygheap-base-mismatch-detected/5359/2 )

openssl upgraded to 1.0.2t, 1.1.0l, 1.1.1d
libressl are upgraded (2.9.2, 2.8.3, 2.7.5)  --> (3.0.2, 2.9.2, 2.8.3)