extend the usability of our linux router binaries

[garypen]

We build our binaries on CircleCI cimg images and this results in building our router linux binaries with a relatively new glibc.

On older (or more conservative) linux distros (for example: Centos 8) this can lead to errors like this:

/lib64/libm.so.6: version `GLIBC_2.29' not found (required by ./dist/router)

We should update our build infrastructure to address this. Possible options:

• Multiple binary distributions for different versions of linux
• Build against an older version of linux to eliminate the problem
• ...

There are various constraints we need to work within whichever solution we choose; mainly around minimum compile environment requirements of rustc.

[marianoqueirel]

Hi team, I'm facing the issue /lib/x86_64-linux-gnu/libc.so.6: version GLIBC_2.29' not found (required by ./router-1.37.0/router)` when running on a Debian 10.