[migrate] Add tag 2.0.6 source code (#8)

Add version 2.0.6 code from https://github.com/apache/dolphinscheduler/tree/2.0.6/dolphinscheduler-python/pydolphinscheduler

setup.py

diff --git a/setup.py b/setup.py
index dae2ed0..f5410ca 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 
 logger = logging.getLogger(__name__)
 
-version = "2.0.5"
+version = "2.0.6"
 
 # Start package required
 prod = [