resolve #176 (#177)

Author: jGaboardi

pointpats/__init__.py

@@ -1,5 +1,5 @@
-__version__ = "2.3.0"
-# __version__ has to be defined in the first line
+import contextlib
+from importlib.metadata import PackageNotFoundError, version
 
 from .pointpattern import PointPattern
 from .window import as_window, poly_from_bbox, to_ccf, Window
@@ -9,3 +9,6 @@
 from .distance_statistics import *
 from .spacetime import *
 from .kde import *
+
+with contextlib.suppress(PackageNotFoundError):
+    __version__ = version("pointpats")