Could exit nicely when python 2/3 don't match

[Matt Wilkie]

Archook could exit more gracefully when python2/3 doesn't match.

A minor would-be-nice-if item.

$ python test\simple-test-arcmap.py
========================================
3.6.10 |Anaconda, Inc.| (default, Mar 23 2020, 17:58:33) [MSC v.1916 64 bit (AMD64)]

--- PRE sys.path:
D:\code\public\archook\test
C:\tools\miniconda3\envs\archook-py36\python36.zip
C:\tools\miniconda3\envs\archook-py36\DLLs
C:\tools\miniconda3\envs\archook-py36\lib
C:\tools\miniconda3\envs\archook-py36
C:\tools\miniconda3\envs\archook-py36\lib\site-packages
d:\code\public\archook
Traceback (most recent call last):
  File "test\simple-test-arcmap.py", line 13, in <module>
    r = archook.get_arcpy()
  File "d:\code\public\archook\archook\archook.py", line 167, in get_arcpy
    verify_bit_match()
  File "d:\code\public\archook\archook\archook.py", line 44, in verify_bit_match
    raise Exception(msg)
Exception: *** Error: python and arcgis 32/64bit mismatch: Py:64, Arc:32