Add initial zookeeper wrapper code

tests/zookeeper_watcher_test.cpp

@@ -0,0 +1,17 @@
+#include <gtest/gtest.h>
+#include "cppkafka/zookeeper/zookeeper_watcher.h"
+
+using std::string;
+
+using namespace cppkafka;
+
+class ZookeeperWatcherTest : public testing::Test {
+public:
+ 
+};
+
+TEST_F(ZookeeperWatcherTest, GetBrokers) {
+    ZookeeperWatcher watcher(ZOOKEEPER_TEST_INSTANCE);
+    string brokers = watcher.get_brokers();
+    EXPECT_EQ(KAFKA_TEST_INSTANCE, brokers);
+}