GitLab

* refined macos tests

* hotfix

* use the same naming for env variables

* refined Travis tests

* refined VSTS Linux part

* cleanup

* added possibility to test Clang at VSTS

* simplified cp command

* refined Appveyor

* run all tests at Appveyor

* refined VSTS Windows part

* return back old MinGW version

* fixed weird MinGW bug

* don't test Python 3.7 at Windows

* disable tree rendering at Appveyor

* give names to scripts in VSTS Windows and artifacts parts

* Update .vsts-ci.yml

* Update test.sh

* fix bugs

* many fixes

* remove duplicate lines

* test for mingw

* Not nuget in appveyor

* remove mingw build

* Update test.sh

* Update test.sh

* Update test.sh

* fixed macOS wheel name

* don't run docs test at VSTS

* made nuget creating script directory independent

This reverts commit f0824da3.