give the commit hash for version flag

IMP

@@ -91,7 +91,9 @@ def select(title, questions):
 CURRENT_PATH = Path('.').abspath()
 
 if __name__ == '__main__':
-    args = docopt(__doc__, version="IMP 1.0", options_first=True)
+    args = docopt(__doc__, version=subprocess.call(
+        ['git', '--no-pager', 'log', '-n', '1', '--pretty=format:%H']
+    ), options_first=True)
     # get config file from cache
     config_files = get_config_cache().split()
     # delete if some config files are removed