convert ligolw_segment_query_dqsegdb to an entry_point

mainly so that its code is in the main library and we can test more easily, and measure coverage

bin/ligolw_segment_query_dqsegdb → dqsegdb/tools/ligolw_segment_query.py

-#!/usr/bin/env python3
-#
 # Copyright (C) 2014-2020 Syracuse University, European Gravitational Observatory, and Christopher Newport University.  Written by Ryan Fisher and Gary Hemming. See the NOTICE file distributed with this work for additional information regarding copyright ownership.
 #
 # This program is free software: you can redistribute it and/or modify
@@ -107,7 +105,7 @@ __formatted_date__ = __date__[0:10] + " " + __date__[11:19] + " +0000"
 #
 
 
-def parse_command_line():
+def parse_command_line(args=None):
     """
     Parse the command line, return an options object
     """
@@ -148,7 +146,7 @@ def parse_command_line():
     parser.add_option("-o", "--output-file",   metavar = "output_file", help = "File to which output should be written.  Defaults to stdout.")
     #parser.add_option("-v", "--debug", metavar="debug", help= "Turn on debugging.")
 
-    options, others = parser.parse_args()
+    options, others = parser.parse_args(args=args)
 
     # Make sure we have exactly one thing to do
     count = 0
@@ -694,7 +692,7 @@ def setup_files(dir_name, gps_start_time, gps_end_time):
 # =============================================================================
 #
 
-if __name__ == '__main__':
+def main(args=None):
     options, database_location, file_location  = parse_command_line()
 
     # Ping the database and exit if requested
@@ -765,3 +763,5 @@ if __name__ == '__main__':
         os.remove(temp_db)
 
 
+if __name__ == '__main__':
+    sys.exit(main())

setup.py

@@ -36,6 +36,11 @@ setup(name=PACKAGENAME,
       packages=packagenames,
       ext_modules=[],
       scripts=scripts,
+      entry_points={
+          "console_scripts": [
+              "ligolw_segment_query_dqsegdb = dqsegdb.tools.ligolw_segment_query:main",
+          ],
+      },
       setup_requires=['setuptools'],
       install_requires=[
           'gpstime',