Add test for removing a user from user discovery

basice2e/clients.goldoutput/client13-2.txt

+Failed to register user josh13: rpc error: code = Unknown desc = Username josh13 is already taken. Please try again

basice2e/clients.goldoutput/client13.txt

@@ -12,3 +12,4 @@ Message received: Hello from Josh31, with E2E Encryption
 Message received: Hello from Josh31, with E2E Encryption
 Message received: Hello from Josh31, with E2E Encryption
 Received 5
+Removed user from discovery: josh13

basice2e/run.sh

@@ -534,6 +534,18 @@ then
     echo "$CLIENTCMD -- $PIDVAL"
     wait $PIDVAL
     wait $PIDVAL2
+
+    # Test Remove User
+    CLIENTCMD="timeout 240s ../bin/client ud $CLIENTUDOPTS -l $CLIENTOUT/client13.log -s blob13 --remove josh13"
+    eval $CLIENTCMD >> $CLIENTOUT/client13.txt || true &
+    PIDVAL=$!
+    echo "$CLIENTCMD -- $PIDVAL"
+    wait $PIDVAL
+    CLIENTCMD="timeout 240s ../bin/client ud $CLIENTUDOPTS -l $CLIENTOUT/client13-2.log -s blob13-2 --register josh13"
+    eval $CLIENTCMD >> $CLIENTOUT/client13-2.txt || true &
+    PIDVAL=$!
+    echo "$CLIENTCMD -- $PIDVAL"
+    wait $PIDVAL
 fi