SyntaxError: invalid syntax due to async being a reserved keyword in Python 3.7

[sebastic]

Description

As reported by Andreas Beckmann in Debian Bug #903784:

during a test with piuparts I noticed your package failed to install. As per definition of the release team this makes the package too buggy for a release, thus the severity.

From the attached log (scroll to the bottom...):

  Selecting previously unselected package python3-pycsw.
  (Reading database ... 
(Reading database ... 9155 files and directories currently installed.)
  Preparing to unpack .../python3-pycsw_2.2.0+dfsg-3_all.deb ...
  Unpacking python3-pycsw (2.2.0+dfsg-3) ...
  Setting up python3-pycsw (2.2.0+dfsg-3) ...
    File "/usr/lib/python3/dist-packages/pycsw/ogc/csw/csw2.py", line 1936
      if self.parent.async:
                         ^
  SyntaxError: invalid syntax
  
    File "/usr/lib/python3/dist-packages/pycsw/ogc/csw/csw3.py", line 2013
      if self.parent.async:
                         ^
  SyntaxError: invalid syntax
  
    File "/usr/lib/python3/dist-packages/pycsw/server.py", line 78
      self.async = False
               ^
  SyntaxError: invalid syntax
  
  dpkg: error processing package python3-pycsw (--configure):
   installed python3-pycsw package post-installation script subprocess returned error exit status 1
  Errors were encountered while processing:
   python3-pycsw

Could this be related to python 3.7?

Environment

• operating system: Debian GNU/Linux unstable
• Python version: 3.7.0 (python3.7/3.7.0-1)
• pycsw version: 2.2.0
• source/distribution
  • git clone
  • DebianGIS/UbuntuGIS
  • PyPI
  • zip/tar.gz
  • other (please specify):
• web server
  • Apache/mod_wsgi
  • CGI
  • other (please specify):

Steps to Reproduce

Build and run pycsw with Python 3.7.

Additional Information

Backwards incompatible syntax changes:

• async and await are now reserved keywords.

https://docs.python.org/3/whatsnew/3.7.html