enable in-place compilation mode for pyximport when used from test runner...

enable in-place compilation mode for pyximport when used from test runner (improves package compatibility)

runtests.py

@@ -1684,7 +1684,7 @@ def runtests(options, cmd_args, coverage=None):
     if options.pyximport_py:
         from pyximport import pyximport
         pyximport.install(pyimport=True, build_dir=os.path.join(WORKDIR, '_pyximport'),
-                          load_py_module_on_import_failure=True)
+                          load_py_module_on_import_failure=True, inplace=True)
 
     result = test_runner.run(test_suite)