Bump psycopg2-binary version to 2.7.5

[remicalixte]

Motivation

It is the first version that provides a binary wheel for python3.7

Review checklist

• PR has a meaningful title or PR has the no-changelog label attached
• Feature or bugfix has tests
• Git history is clean
• If PR impacts documentation, docs team has been notified or an issue has been opened on the documentation repo
• If PR adds a configuration option, it has been added to the configuration file.

[codecov-io]

Codecov Report

Merging #2799 into master will decrease coverage by 9.1%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2799      +/-   ##
==========================================
- Coverage   84.73%   75.63%   -9.11%     
==========================================
  Files         663       45     -618     
  Lines       37838     3263   -34575     
  Branches     4546      386    -4160     
==========================================
- Hits        32063     2468   -29595     
+ Misses       4435      699    -3736     
+ Partials     1340       96    -1244

[codecov-io]

Codecov Report

Merging #2799 into master will decrease coverage by 7.54%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2799      +/-   ##
==========================================
- Coverage   84.73%   77.19%   -7.55%     
==========================================
  Files         663       60     -603     
  Lines       37838     4201   -33637     
  Branches     4546      506    -4040     
==========================================
- Hits        32063     3243   -28820     
+ Misses       4435      814    -3621     
+ Partials     1340      144    -1196

[ofek]

Thanks!