Rework tests check all wheels produced against a reference list

Also, wrap the cibuildwheel call to make building env easier

test/03_before_build/cibuildwheel_test.py

@@ -1,22 +1,18 @@
-import subprocess, sys, os
-from glob import glob
+import os
 import utils
 
 def test():
     project_dir = os.path.dirname(__file__)
-    # set up the environment
-    env = os.environ.copy()
-    # write python version information to a temporary file, this is checked
-    # in setup.py
-    env.update({
+
+    # build the wheels
+    utils.run_cibuildwheel(project_dir, add_env={
+        # write python version information to a temporary file, this is
+        # checked in setup.py
         'CIBW_BEFORE_BUILD': '''python -c "import sys; open('/tmp/pythonversion.txt', 'w').write(sys.version)" && python -c "import sys; open('/tmp/pythonexecutable.txt', 'w').write(sys.executable)"''',
         'CIBW_BEFORE_BUILD_WINDOWS': '''python -c "import sys; open('c:\\pythonversion.txt', 'w').write(sys.version)" && python -c "import sys; open('c:\\pythonexecutable.txt', 'w').write(sys.executable)"''',
     })
-
-    # build the wheels
-    subprocess.check_call([sys.executable, '-m', 'cibuildwheel', project_dir], env=env)
     
-    # check that we got the right number of built wheels
-    expected_identifiers = utils.cibuildwheel_get_build_identifiers(project_dir)
-    built_wheels = glob('wheelhouse/*.whl')
-    assert len(built_wheels) == len(expected_identifiers)
+    # also check that we got the right wheels
+    expected_wheels = utils.expected_wheels('spam', '0.1.0')
+    actual_wheels = os.listdir('wheelhouse')
+    assert set(actual_wheels) == set(expected_wheels)