Fix odometry sign error

Add warning in code regarding Create 1 odometry issue
Add odom_example.cpp

examples/odom_example.cpp

@@ -0,0 +1,50 @@
+#include "create/create.h"
+
+create::Create* robot;
+
+int main(int argc, char** argv) {
+  std::string port = "/dev/ttyUSB0";
+  int baud = 115200;
+  create::RobotModel model = create::CREATE_2;
+
+  if (argc > 1 && std::string(argv[1]) == "create1") {
+    model = create::CREATE_1;
+    baud = 57600;
+    std::cout << "1st generation Create selected" << std::endl;
+  }
+
+  robot = new create::Create(model);
+
+  // Attempt to connect to Create
+  if (robot->connect(port, baud))
+    std::cout << "Successfully connected to Create" << std::endl;
+  else {
+    std::cout << "Failed to connect to Create on port " << port.c_str() << std::endl;
+    return 1;
+  }
+
+  robot->setMode(create::MODE_FULL);
+
+  usleep(1000000);
+
+  // drive in a circle
+  robot->drive(0.1, 0.5);
+
+  // Quit when center "Clean" button pressed
+  while (!robot->isCleanButtonPressed()) {
+    create::Pose pose = robot->getPose();
+
+    std::cout << "x: " << pose.x
+              << "\ty: " << pose.y
+              << "\tyaw: " << pose.yaw * 180.0/create::util::PI << std::endl;
+  
+    usleep(1000 * 100); //10hz
+  }
+
+  std::cout << "Stopping Create." << std::endl;
+
+  robot->disconnect();
+  delete robot;
+
+  return 0;
+}