bump OpenCV to 3.4.3

Merge pull request opencv#111 from kvalev/patch-1

Create x86_64 Linux wheels for Python 3.7

add missing identifier for 3.7

bump OpenCV version to 3.4.1

upload fails on macOS due to too old SSL

change version parsing logic, old one does not work in Docker

remove cherry-pick

bump OpenCV version to 3.3.1

Add Qt 4.8.7 for GUI support to Linux and macOS builds

update import behaviour