Replace rules_pip with rules_python; use bazel built upstream grpc
instead of Python packages

As usual with Python sadness, the @pydeps wheels are built on the bazel
host, so stuffing them inside a container_image (or py_image) will cause
new and unexpected kinds of misery.

Change-Id: Id4e4d53741cf2da367f01aa15c21c133c5cf0dba
diff --git a/hswaw/lib/flask_spaceauth/BUILD b/hswaw/lib/flask_spaceauth/BUILD
index 9060d58..4c29872 100644
--- a/hswaw/lib/flask_spaceauth/BUILD
+++ b/hswaw/lib/flask_spaceauth/BUILD
@@ -1,8 +1,12 @@
+load("@pydeps//:requirements.bzl", "requirement")
+
 py_binary(
     name = "example",
     srcs = ["example.py"],
     deps = [
         "//hswaw/lib/flask_spaceauth/spaceauth",
-        "@pydeps//flask",
+        requirement("flask"),
+        requirement("werkzeug"),
+        requirement("itsdangerous"),
     ]
 )