Prevent traceback with non-exec interpreter

Fixes #121

Add tests for virtualenv  with nose and mock
Add helper method to virtualenv for is_executable
Raise SystemExit rather than sys.exit directly

Tested on 2.4.4, 2.7.1 and 3.2

1 files changed, 2 insertions, 0 deletions

diff --git a/setup.py b/setup.py
index dad8605..3815afb 100644
--- a/setup.py
+++ b/setup.py
@@ -52,5 +52,7 @@ setup(name='virtualenv',
       py_modules=['virtualenv'],
       packages=['virtualenv_support'],
       package_data={'virtualenv_support': ['*-py%s.egg' % sys.version[:3], '*.tar.gz']},
+      test_suite='nose.collector',
+      tests_require=['nose', 'Mock'],
       **kw
       )