Added __version__ attribute to root package (#155)

* Fixed segy version issue

* Added a newline

---------

Co-authored-by: Amit.Pendharkar <Amit.Pendharkar@tgs.com>

src/segy/__init__.py

@@ -1,6 +1,12 @@
 """'The' SEG-Y implementation."""
+from importlib import metadata
 
 from segy.factory import SegyFactory
 from segy.file import SegyFile
 
 __all__ = ["SegyFile", "SegyFactory"]
+
+try:
+    __version__ = metadata.version("segy")
+except metadata.PackageNotFoundError:
+    __version__ = "unknown"