Move Python version check to __init__.py
This allows the version check to work properly
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+import sys
+
+if sys.version_info.major == 2:
+ print("aqtinstall requires python 3!")
+ sys.exit(1)
+
from aqt.installer import Cli
from aqt.version import __version__
