tests: move buffer tests to src/vlib/test

- Refactor make test code to be co-located with
  the vpp feature source code.

Type: test

Signed-off-by: Dave Wallace <[email protected]>
Change-Id: Id3f856d9c8de1695edd5b968b8acfa2b382a0139

diff --git a/test/test_buffers.py b/src/vlib/test/test_buffers.py
similarity index 100%
rename from test/test_buffers.py
rename to src/vlib/test/test_buffers.py