utils: add simple HTTP Bearer authentication class

passerelle/utils/http_authenticators.py

@@ -68,3 +68,18 @@ class HawkAuth(AuthBase):
     def __call__(self, r):
         r.headers['Authorization'] = self.get_authorization_header(r)
         return r
+
+
+class HttpBearerAuth(AuthBase):
+    def __init__(self, token):
+        self.token = token
+
+    def __eq__(self, other):
+        return self.token == getattr(other, 'token', None)
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __call__(self, r):
+        r.headers['Authorization'] = 'Bearer ' + self.token
+        return r