Fixing Opserver UT

Currently Opserver UT is failing in R3.2 branch because of following issues.
1. In latest release of pip, url_to_path handling has changed via pypa/pip#5892.
   This is breaking Opserver UT in R3.2. But It works in latest master.
   Fix - Make R3.2 opserver/Sconsript same as master.

2. Cassandra 2.1.9 is not spawning by mockcassandra.
   Fix - This cassandra version is affected by https://issues.apache.org/jira/browse/CASSANDRA-11661.
   Upgrade cassandra version to 2.2.12. This is same as cassandra version running on 3.2.13 deployments.
   Mockcassandra is using pycassa to connect to cassandra on thrift port. So, set start_rpc TRUE in cassandra yaml.

Change-Id: I0d62d6a6487f284cc56bb904da6d5ba5ba191833
closes-jira-bug: CEM-5615

src/analytics/test/utils/mockcassandra/mockcassandra/mockcassandra.py

@@ -33,7 +33,7 @@ def start_cassandra(cport, sport_arg=None, cassandra_user=None, cassandra_passwo
     Arguments:
         cport : An unused TCP port for Cassandra to use as the client port
     '''
-    cassandra_version = '2.1.9'
+    cassandra_version = '2.2.12'
     cassandra_url = cassandra_bdir + '/apache-cassandra-'+cassandra_version+'-bin.tar.gz'
 
     if not os.path.exists(cassandra_bdir):
@@ -84,7 +84,8 @@ def start_cassandra(cport, sport_arg=None, cassandra_user=None, cassandra_passwo
         (cport, cqlport, thriftport))
 
     replace_string_(confdir + "cassandra.yaml", \
-        [("rpc_port: 9160","rpc_port: " + str(thriftport)), \
+        [("start_rpc: false", "start_rpc: true"), \
+        ("rpc_port: 9160","rpc_port: " + str(thriftport)), \
         ("storage_port: 7000","storage_port: " + str(sport)),
         ("native_transport_port: 9042","native_transport_port: " + str(cqlport))])
 

src/opserver/SConscript

@@ -227,7 +227,6 @@ sandesh_pkgs = [vm_pkg, vn_pkg, stats_test_pkg, alarm_test_pkg,
 testr_str = 'bash -c "set -o pipefail && cd ' + Dir(top_dir).path + \
             ' && tools_path=../config/common/tests/' + \
             ' omit_list="opserver/sandesh"' \
-            ' build_top=' + Dir(OpEnv['TOP']).path + \
             ' CFLAGS= LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../../../build/lib' \
             ' python setup.py run_tests %s 2>&1 |' \
             ' tee %s.log"'