add kerberos dependency (#99)

Author: tovganesh

setup.py

@@ -66,7 +66,8 @@ def _get_dbt_core_version():
     install_requires=[
         'dbt-core~={}'.format(dbt_core_version),
         "impyla==0.18",
-        "python-decouple>=3.6"
+        "python-decouple>=3.6",
+        "kerberos>=1.3.0",
     ],
     classifiers=[
         "Development Status :: 4 - Beta",