renaming plain-text file "VERISON" to "VERSION.py" and explicitly imp…

…orting in `__version__.py` so pyinstaller will automatically detect VERSION as a dependency. (#37)

The original method using a plain text file results in a run-time error when pyinstaller is used to generate a single file executable with the following line:

`pyinstaller -F -w <hart_protocol_user_script.py>`

where `<hart_protocol_user_script.py>` is a script that imports `hart_protocol`

pyinstaller was not detecting file *VERSION* as a required dependency and it wasn't being included in the executable image.  There may also be another method of resolving this issue on the pyinstaller side by using --add-data or possibly a hook file (my first attempts were not successful).

Co-authored-by: Brian Amos <amos@sensornetworksinc.com>

hart_protocol/VERSION.py

@@ -0,0 +1 @@
+__version__ = "2023.5.0"

hart_protocol/__version__.py

@@ -3,18 +3,14 @@
 
 import pathlib
 import subprocess
+from .VERSION import __version__
 
 
 here = pathlib.Path(__file__).resolve().parent
 
 
 __all__ = ["__version__", "__branch__"]
 
-
-# read from VERSION file
-with open(str(here / "VERSION")) as f:
-    __version__ = f.read().strip()
-
 try:
     __branch__ = (
         subprocess.run(["git", "branch", "--show-current"], capture_output=True, cwd=here)