Add string representation to _RequestObjectProxy

Via https://github.com/openstack/requests-mock/pull/12 by @allardhoeve

Change-Id: I7e9bba3a22a08ee41af5480b8a3cee49ef06624d

.gitignore

@@ -34,6 +34,7 @@ htmlcov
 .mr.developer.cfg
 .project
 .pydevproject
+.idea
 
 # Complexity
 output/*.html

requests_mock/request.py

@@ -152,3 +152,6 @@ class _RequestObjectProxy(object):
         the matcher is not available it will return None.
         """
         return self._matcher()
+
+    def __str__(self):
+        return "{0.method} {0.url}".format(self._request)

requests_mock/tests/test_request.py

@@ -117,3 +117,7 @@ class RequestTests(base.TestCase):
         self.assertEqual('host.example.com', req.netloc)
         self.assertEqual('host.example.com', req.hostname)
         self.assertEqual(443, req.port)
+
+    def test_to_string(self):
+        req = self.do_request(url='https://host.example.com/path')
+        self.assertEqual('GET https://host.example.com/path', str(req))