Merge pull request #41 from AlJohri/patch-1

use ASDF_DIR env var to test if ASDF is installed

src/pythonfinder/environment.py

@@ -7,7 +7,7 @@
 PYENV_INSTALLED = bool(os.environ.get("PYENV_SHELL")) or bool(
     os.environ.get("PYENV_ROOT")
 )
-ASDF_INSTALLED = bool(os.environ.get("ASDF_DATA_DIR"))
+ASDF_INSTALLED = bool(os.environ.get("ASDF_DIR"))
 PYENV_ROOT = os.path.expanduser(
     os.path.expandvars(os.environ.get("PYENV_ROOT", "~/.pyenv"))
 )