Add wheel to tests_require
Add wheel to tests_require

Speculative. Not sure why it’s suddenly needed.

https://github.com/jakubroztocil/httpie/runs/845338452

jkbrzt/httpie,PKRoma/httpie,PKRoma/httpie,jakubroztocil/httpie,jkbrzt/httpie,jkbrzt/httpie,jakubroztocil/httpie,jakubroztocil/httpie