Make it possible to build package via PEP 517

setup.py

@@ -9,6 +9,7 @@
 ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ##
 """Build helper."""
 
+import os.path
 import sys
 
 from setuptools import setup
@@ -19,6 +20,11 @@
         "You are using %s" % sys.version
     )
 
+# This is needed for versioneer to be importable when building with PEP 517.
+# See <https://github.com/warner/python-versioneer/issues/193> and links
+# therein for more information.
+sys.path.append(os.path.dirname(__file__))
+
 try:
     import versioneer