Switch to OpenSSL 1.1.1

[anton-trunov]

According to https://www.openssl.org/policies/releasestrat.html,

Version 1.0.2 will be supported until 2019-12-31 (LTS).

But

Version 1.1.1 will be supported until 2023-09-11 (LTS).

Incidentally, macOS's Homebrew package manager already dropped 1.0.2, see Homebrew/homebrew-core#46454

[anton-trunov]

FWIW, a related issue -- #690

[anton-trunov]

Also, I've seen a couple reports saying OpenSSL 1.1.1 works fine (although I don't know if the reporters ran the tests or just compiled Scilla). On macOS 10.14.6 Mojave OpenSSL v1.1.1 compiles fine, but the tests fail:

ulimit -s 128 -n 1024; dune exec tests/polynomials/testsuite_polynomials.exe
........
Ran: 8 tests in: 0.15 seconds.
OK
ulimit -s 128 -n 1024; dune exec tests/base/testsuite_base.exe -- -print-diff true
...........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................EE..........................
==============================================================================
Error: all_tests:4:signature_tests:0:schnorr_tests:1.

File "/Users/anton/zilliqa/scilla/_build/oUnit-all_tests-Antons-MacBook-Pro.local#00.log", line 8454, characters 1-1:
Error: all_tests:4:signature_tests:0:schnorr_tests:1 (in the log).

Worker stops running: Killed by signal -10
------------------------------------------------------------------------------
==============================================================================
Error: all_tests:4:signature_tests:0:schnorr_tests:0.

File "/Users/anton/zilliqa/scilla/_build/oUnit-all_tests-Antons-MacBook-Pro.local#00.log", line 8450, characters 1-1:
Error: all_tests:4:signature_tests:0:schnorr_tests:0 (in the log).

Worker stops running: Killed by signal -10
------------------------------------------------------------------------------
Ran: 519 tests in: 9.78 seconds.
FAILED: Cases: 519 Tried: 519 Errors: 2 Failures: 0 Skip:  0 Todo: 0 Timeouts: 0.
make: *** [test] Error 1

Also, the CI currently uses version 1.0.2

[anton-trunov]

Fixed with PR #746