fix install without DesiTest

setup.py

@@ -15,7 +15,7 @@
 #
 # DESI support code.
 #
-from desiutil.setup import DesiTest, DesiVersion, get_version
+from desiutil.setup import DesiVersion, get_version
 #
 # Begin setup
 #
@@ -56,7 +56,7 @@
 # setup_keywords['use_2to3'] = False
 setup_keywords['packages'] = find_packages('py')
 setup_keywords['package_dir'] = {'':'py'}
-setup_keywords['cmdclass'] = {'version': DesiVersion, 'test': DesiTest, 'sdist': DistutilsSdist}
+setup_keywords['cmdclass'] = {'version': DesiVersion, 'sdist': DistutilsSdist}
 setup_keywords['test_suite']='{name}.test.{name}_test_suite.{name}_test_suite'.format(**setup_keywords)
 #
 # Autogenerate command-line scripts.
@@ -74,6 +74,14 @@
                                                'data/*.yaml',
                                                'data/*.dat',],
                                   'desispec.test': ['data/ql/*',]}
+
+#
+# Print informative message if user tried "python setup.py test"
+#
+if "test" in sys.argv:
+    print("Please run pytest instead")
+    sys.exit(1)
+
 #
 # Run setup command.
 #