Update to 1.88
    
    - New upstream release 1.88
      Summary of major changes since version 1.85
      - Mike McCauley has stepped down as maintainer: the new maintainers are Chris
        Novakovic, Heikki Vatiainen and Tuure Vartiainen
      - The source code has moved from the now-defunct Debian Subversion server
        (alioth.debian.org) to GitHub
        (https://github.com/radiator-software/p5-net-ssleay)
      - Net-SSLeay is provided under the terms of the Artistic License 2.0; this
        has been the case since version 1.66, but references to other licenses
        remained in the source code, causing ambiguity
      - Perl 5.8.1 or newer is now required to use Net-SSLeay; this has already
        been the case for some time in practice, as the test suite hasn't fully
        passed on Perl 5.6 for several years
      - Much-improved compatibility with OpenSSL 1.1.1, and improved support for
        TLS 1.3
      - Fixed a long-standing bug in cb_data_advanced_put() that caused memory
        leaks when callbacks were frequently added and removed
      - Support in the test suite for "hardened" OpenSSL configurations that set a
        default security level of 2 or higher (e.g., in the OpenSSL packages that
        ship with recent versions of Debian, Fedora and Ubuntu)