Upgrade the version of sagemaker-inference (#53)

Author: ajaykarpur

setup.py

@@ -47,7 +47,7 @@ def read(fname):
         'Programming Language :: Python :: 3.6',
     ],
     install_requires=['numpy==1.16.4', 'Pillow==6.2.0', 'retrying==1.3.3', 'sagemaker-containers==2.5.4',
-                      'six==1.12.0', 'requests_mock==1.6.0', 'sagemaker-inference==1.1.2',
+                      'six==1.12.0', 'requests_mock==1.6.0', 'sagemaker-inference==1.2.0',
                       'retrying==1.3.3'],
     extras_require={
         'test': ['boto3==1.10.32', 'coverage==4.5.3', 'docker-compose==1.23.2', 'flake8==3.7.7', 'Flask==1.1.1',