Create __main__.py (Fixes #15) (#38)

This adds a main method that mimics the behavior of `rm`. It can be called via `python -m send2trash somefile`.

tests/test_script_main.py

@@ -0,0 +1,32 @@
+# encoding: utf-8
+import os
+import unittest
+from tempfile import NamedTemporaryFile
+from os import path as op
+
+from send2trash.__main__ import main as trash_main
+from tests.test_plat_other import HOMETRASH
+
+
+class TestMainTrash(unittest.TestCase):
+    def setUp(self):
+        self.file = NamedTemporaryFile(dir=op.expanduser('~'), prefix='send2trash_test', delete=False)
+
+    def test_trash(self):
+        trash_main(['-v', self.file.name])
+        self.assertFalse(op.exists(self.file.name))
+
+    def test_no_args(self):
+        self.assertRaises(SystemExit, trash_main, [])
+        self.assertRaises(SystemExit, trash_main, ['-v'])
+        self.assertTrue(op.exists(self.file.name))
+        trash_main([self.file.name])  # Trash the file so tearDown runs properly
+
+    def tearDown(self):
+        name = op.basename(self.file.name)
+        os.remove(op.join(HOMETRASH, 'files', name))
+        os.remove(op.join(HOMETRASH, 'info', name + '.trashinfo'))
+
+
+if __name__ == '__main__':
+    unittest.main()