Fix encoding regression

docker/linux/Dockerfile

@@ -1,2 +1,2 @@
 FROM jongallant/iotedgedev-deps:${VERSION}-linux
-RUN pip install azure-iot-edge-dev-tool
+RUN pip install -U azure-iot-edge-dev-tool

docker/linux/Dockerfile.expanded

@@ -1,2 +1,2 @@
-FROM jongallant/iotedgedev-deps:0.0.13-linux
-RUN pip install azure-iot-edge-dev-tool
+FROM jongallant/iotedgedev-deps:0.57.0-linux
+RUN pip install -U azure-iot-edge-dev-tool

iotedgedev/iotedgedev.py

@@ -171,7 +171,7 @@ class Utility:
             return file.read()
 
     def decode(self, val):
-        return val.decode('unicode_escape').strip()
+        return val.decode("utf-8").strip()
 
     def get_config_files(self):
         config_dir = "config"