scripts: unit-test: add missing regex typing

Prepend regex string with "r"

Change-Id: Id448e3a7fead65650f9956eb948e4afe63e45204
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/scripts/unit-test.py b/scripts/unit-test.py
index 378e7db..16ffa11 100755
--- a/scripts/unit-test.py
+++ b/scripts/unit-test.py
@@ -484,7 +484,7 @@
 
     # DEPENDENCIES_REGEX = [GIT REPO]:[REGEX STRING]
     DEPENDENCIES_REGEX = {
-        'phosphor-logging': '\S+-dbus-interfaces$'
+        'phosphor-logging': r'\S+-dbus-interfaces$'
     }
 
     # Set command line arguments