Remove surrounding quotes from TLS paths, if present

Signed-off-by: Joffrey F <joffrey@docker.com>

tests/unit/cli/utils_test.py

@@ -0,0 +1,23 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import unittest
+
+from compose.cli.utils import unquote_path
+
+
+class UnquotePathTest(unittest.TestCase):
+    def test_no_quotes(self):
+        assert unquote_path('hello') == 'hello'
+
+    def test_simple_quotes(self):
+        assert unquote_path('"hello"') == 'hello'
+
+    def test_uneven_quotes(self):
+        assert unquote_path('"hello') == '"hello'
+        assert unquote_path('hello"') == 'hello"'
+
+    def test_nested_quotes(self):
+        assert unquote_path('""hello""') == '"hello"'
+        assert unquote_path('"hel"lo"') == 'hel"lo'
+        assert unquote_path('"hello""') == 'hello"'