add tests coverage percent in gitlab

This pipeline will fail because of #1268 (closed), it will be necessary to wait for the MR !1245 (merged) merged which solves the problem, then a rebase on 1.6 for this pipeline to succeed.

added 9 commits

• 1c6c8e4f...ec1189e2 - 6 commits from branch 1.6
• f36f325a - try to print coverage percent
• e26e9ca1 - [fix] sed command (coverage)
• a117cdce - Merge branch 'coverage' of git.duniter.org:nodes/typescript/duniter into coverage

Compare with previous version

mentioned in commit 6cd5c513

merged