update setup and readme

tox.ini

@@ -6,7 +6,7 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 install_command =
                   constraints: {[testenv:common-constraints]install_command}
-                  pip install -U {opts} {packages} --trusted-host pypi.douban.com
+                  pip install -U {opts} {packages}
 commands = nosetests --with-coverage --cover-erase --cover-package=opensearchsdk
 
 [testenv:pep8]