Fix pip-sync to use pip script depending on a python version

[atugushev]

Fixes #734.

Changelog-friendly one-liner: Fix pip-sync to use pip script depending on a python version

Contributor checklist

• Provided the tests for the changes.
• Requested a review from another contributor.
• Gave a clear one-line description in the PR (that the maintainers can add to CHANGELOG.md on release).
• Assign the PR to an existing or new milestone for the target version (following Semantic Versioning).

[codecov]

Codecov Report

Merging #737 into master will increase coverage by 0.15%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #737      +/-   ##
==========================================
+ Coverage   85.81%   85.96%   +0.15%     
==========================================
  Files          31       31              
  Lines        2122     2124       +2     
  Branches      305      304       -1     
==========================================
+ Hits         1821     1826       +5     
+ Misses        233      232       -1     
+ Partials       68       66       -2

Impacted Files	Coverage Δ
tests/test_sync.py	98.44% <100%> (+0.06%)	⬆️
piptools/sync.py	81.91% <100%> (+2.53%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ede4c62...18d05c0. Read the comment docs.

[blueyed]

Awesome!

[vphilippon]

👍
(Please keep them coming!)

[kb-1000]

Awesome, this even fixes another issue I had (importing piptools and running it inside another script)!

[kb-1000]

When can I expect a release including this fix?

[vphilippon]

@kaeptmblaubaer1000 I'm preparing a release right now. Taking the CI time into account, in the next few hours.

[vphilippon]

pip-tools v3.4.0 released