[#63128668] changes in network_test.py and checked with network output. they are correct.
ramki@ubuntu:~/git/tethne/testsuite$ python -m unittest -v networks_test
test_node_attribs_check (networks_test.TestAuthorCoinstitution) ... ok
test_shared_institutions_one (networks_test.TestAuthorCoinstitution) ... ok
test_shared_institutions_two (networks_test.TestAuthorCoinstitution) ... ok
test_shared_institutions_zero (networks_test.TestAuthorCoinstitution) ... ok