swc-installation-test-2.py: Don't override Popen's 'close_fds'

Or 'shell'.  The support for these options can be flaky, and the
defaults change with Python version depending on what is best
supported [1].

[1]: http://docs.python.org/2/library/subprocess.html#subprocess.Popen

Reported-by: Ethan White <ethan@weecology.org>

setup/swc-installation-test-2.py

@@ -416,7 +416,7 @@ def _get_version_stream(self, stdin=None, expect=(0,)):
             p = _subprocess.Popen(
                 [command] + list(self.version_options), stdin=popen_stdin,
                 stdout=_subprocess.PIPE, stderr=_subprocess.PIPE,
-                close_fds=True, shell=False, universal_newlines=True)
+                universal_newlines=True)
         except OSError as e:
             raise DependencyError(
                 checker=self,