Add logging of populated repo

[rbikar]

Logs of ubipop are difficult read, let's add
logging of currently populated repos in order
to improve readability of log.

[codecov-commenter]

Codecov Report

Merging #162 (c5d47c2) into master (929f916) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #162      +/-   ##
==========================================
+ Coverage   92.53%   92.56%   +0.03%     
==========================================
  Files           5        5              
  Lines         897      901       +4     
==========================================
+ Hits          830      834       +4     
  Misses         67       67              

Impacted Files	Coverage Δ
ubipop/__init__.py	85.66% <100.00%> (+0.18%)	⬆️

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