Add sys_info utility to display dependencies version

[mscheltienne]

Helpful tool for CIs.

[codecov]

Codecov Report

Merging #122 (61352e4) into main (a8416cc) will decrease coverage by 0.36%.
The diff coverage is 78.37%.

@@            Coverage Diff             @@
##             main     #122      +/-   ##
==========================================
- Coverage   89.99%   89.63%   -0.36%     
==========================================
  Files          30       32       +2     
  Lines        2648     2722      +74     
  Branches      509      523      +14     
==========================================
+ Hits         2383     2440      +57     
- Misses        155      168      +13     
- Partials      110      114       +4     

Files Changed	Coverage Δ
pycrostates/commands/sys_info.py	0.00% <0.00%> (ø)
pycrostates/utils/sys_info.py	86.56% <86.56%> (ø)

... and 1 file with indirect coverage changes