Update git submodules

* Update swift from branch 'master'
  to 0550bd4a0ab8e58ff83b7274b033cf3cd7f61552
  - Merge "container/test_server: cleanup Timestamp usage"
  - container/test_server: cleanup Timestamp usage

    * Fix some test assertions w.r.t. Timestamp.internal vs
      Timestamp.normal.

    * Clarify Timestamp format usage in tests.

    Change-Id: I629b49d103a4392833dbdb14224eb20403b09a11
    Signed-off-by: Alistair Coles <alistairncoles@gmail.com>

diff --git a/swift b/swift
index 9059935f9f532031259f50410892f139331f24ad..0550bd4a0ab8e58ff83b7274b033cf3cd7f61552 160000 (submodule)
--- a/swift
+++ b/swift
@@ -1 +1 @@
-Subproject commit 9059935f9f532031259f50410892f139331f24ad
+Subproject commit 0550bd4a0ab8e58ff83b7274b033cf3cd7f61552