change: we now require ngx_lua v0.10.16 and ngx_stream_lua v0.0.8.

[thibaultcha]

I hereby granted the copyright of the changes in this pull request
to the authors of this lua-resty-core project.

Sister PRs:

• bugfix: ensured the 'pcre_version' symbol is preserved and undefined when PCRE is statically linked. lua-nginx-module#1556
• bugfix: ensured the 'pcre_version' symbol is preserved and undefined when PCRE is statically linked. stream-lua-nginx-module#168