Fix weaave happy py3 bug

-- Previous pr "Fix null version case for
VersionList::Parser::GetVersion" change miss
testWdmClientDataSinkSetFlushInvalidInstanceId python3 adjustment since that PR happens before happy python3 upgrade, we
fix the python3 syntax error in this PR.

-- Previous travis ci point to particular happy python3 branch, now
switch to master branch.
diff --git a/.travis/before_install.sh b/.travis/before_install.sh
index dcf8148..dc8f560 100755
--- a/.travis/before_install.sh
+++ b/.travis/before_install.sh
@@ -160,7 +160,7 @@
         installdeps "happy-deps"
 
         cd $HOME
-        git clone --single-branch --branch feature/happy_py3_support https://github.com/openweave/happy.git
+        git clone https://github.com/openweave/happy.git
         cd ${HOME}/happy
         make install
         python3 pip_packages.py
diff --git a/src/test-apps/happy/lib/WeaveDeviceManager.py b/src/test-apps/happy/lib/WeaveDeviceManager.py
index 5fb0de0..1fc2029 100644
--- a/src/test-apps/happy/lib/WeaveDeviceManager.py
+++ b/src/test-apps/happy/lib/WeaveDeviceManager.py
@@ -547,14 +547,14 @@
 
 def testWdmClientDataSinkSetFlushInvalidInstanceId(testObject):
     testObject.createWdmClient()
-    localeSettingsTrait = testObject.newDataSink(20, 1, "/")
-    TestCTrait = testObject.newDataSink(593165827, 0, "/")
-    testObject.setData(localeSettingsTrait, "/1", "en-US")
-    testObject.setData(TestCTrait, "/1", False)
-    testObject.setData(TestCTrait, "/2", 15)
-    testObject.setData(TestCTrait, "/3/1", 16)
-    testObject.setData(TestCTrait, "/3/2", False)
-    testObject.setData(TestCTrait, "/4", 17)
+    localeSettingsTrait = testObject.newDataSink(20, 1, b"/")
+    TestCTrait = testObject.newDataSink(593165827, 0, b"/")
+    testObject.setData(localeSettingsTrait, b"/1", b"en-US")
+    testObject.setData(TestCTrait, b"/1", False)
+    testObject.setData(TestCTrait, b"/2", 15)
+    testObject.setData(TestCTrait, b"/3/1", 16)
+    testObject.setData(TestCTrait, b"/3/2", False)
+    testObject.setData(TestCTrait, b"/4", 17)
     result = testObject.flushUpdate()
     if len(result) != 1:
         raise ValueError("testWdmClientDataSinkSetFlushInvalidInstanceId fails")
@@ -562,12 +562,12 @@
         if not (result[0].profileId == 0xb and result[0].statusCode == 0x21):
             raise ValueError("testWdmClientDataSinkSetFlushInvalidInstanceId profileId and StatusCode check fails")
 
-        print "clear trait: " + str(result[0].dataSink.profileId)
-        print "clear trait path:" + str(result[0].path)
-        testObject.deleteData(result[0].dataSink, result[0].path)
+        print("clear trait: " + str(result[0].dataSink.profileId))
+        print("clear trait path:" + str(result[0].path))
+        testObject.deleteData(result[0].dataSink, result[0].path.encode("utf-8"))
 
     testObject.closeWdmClient()
-    print "testWdmClientDataSinkSetFlushInvalidInstanceId completes"
+    print("testWdmClientDataSinkSetFlushInvalidInstanceId completes")
 
 def RunWdmClientTest():
     print("Run Weave Data Management Test")
@@ -711,7 +711,7 @@
 
         """
         #Disable unregister since the service automatically removes devices from accounts when they are paired again
-        print "Register NestService done"
+        print("Register NestService done")
 
         print ''
         print '#################################unregister-real-NestService#################################'
@@ -721,7 +721,7 @@
             print str(ex)
             exit()
 
-        print "Unregister service done"
+        print("Unregister service done")
         """
         print('')
         print('#################################close#################################')