Further cleaned up the exception handling here to make sense on both

windows and non-windows, Python 2 and 3.

On Python 3 EnvironmentError is an alias for OSError.  On Python 2
WindowsError is a subclass of EnvironmentError.  So this will correctly
check the windows error, if it exists, in all cases.

On Travis we also need to catch ENXIO on Linux, and for some reason
EOPNOTSUPP on OSX.

psutil/tests/__init__.py

@@ -396,16 +396,19 @@ def wait_for_file(fname, timeout=GLOBAL_TIMEOUT, empty=False,
             if delete_file:
                 os.remove(fname)
             return data
-        except (IOError, OSError) as exc:
-            if not ((sys.platform.startswith('win') and
-                    exc.winerror == ERROR_SHARING_VIOLATION) or
-                    exc.errno == errno.ENOENT):
+        except EnvironmentError as exc:
+            posix_errno = exc.errno
+            win_errno = getattr(exc, 'winerror', None)
+
+            if (posix_errno in (errno.ENOENT, errno.ENXIO, errno.EOPNOTSUPP) or
+                    win_errno == ERROR_SHARING_VIOLATION):
                 # In Windows deleting the temporary file can fail if some
                 # process is still holding it open, so retry in that case
+                time.sleep(sleep_for)
+                sleep_for = min(sleep_for * 2, 0.01)
+            else:
                 raise
 
-            time.sleep(sleep_for)
-            sleep_for = min(sleep_for * 2, 0.01)
     raise RuntimeError(
         "timed out after %s secs (couldn't read file)" % timeout)