Avoid requiring admin rights on Windows

This fixes an error on Windows (I'm on with Python 3.7) where the symlink cannot be created without admin rights.

https://github.com/fedora-python/tox-current-env/pull/24

src/tox_current_env/hooks.py

@@ -1,5 +1,6 @@
 import os
 import shutil
+import subprocess
 import sys
 import tox
 
@@ -134,7 +135,11 @@ def tox_testenv_create(venv, action):
         target = sys.executable
         rm_venv(venv)
         os.makedirs(os.path.dirname(link))
-        os.symlink(target, link)
+        if sys.platform == "win32":
+            # Avoid requiring admin rights on Windows
+            subprocess.check_call(f'mklink /J "{link}" "{target}"', shell=True)
+        else:
+            os.symlink(target, link)
         # prevent tox from creating the venv
         return True
     if not is_proper_venv(venv):