test: Move trigger objects to dedicated thread

Put the trigger object in its own thread rather than
the inventory manager thread.  This allows the thread
under test to make calls to it.

Change-Id: I181d2d46a10e4193653df61205ac3380a1d4db2e
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/example/events.d/match1.yaml b/example/events.d/match1.yaml
index d419c74..2219c9f 100644
--- a/example/events.d/match1.yaml
+++ b/example/events.d/match1.yaml
@@ -6,12 +6,12 @@
       description: >
           Sets the value of ExampleProperty1 on /changeme
           when the value of ExampleProperty2 on
-          /testing/inventory/trigger2 changes to yyyxxx.
+          /testing/trigger2 changes to yyyxxx.
       type: match
       signatures:
           - type: signal
             interface: org.freedesktop.DBus.Properties
-            path: /testing/inventory/trigger2
+            path: /testing/trigger2
             member: PropertiesChanged
       filters:
           - name: propertyChangedTo