Changed the implementation of open_fence and open_fence_within me…

…thods.

Updated README

README.md

@@ -62,11 +62,14 @@ Then use `n` to open a geofence like this:
 3) Open a static `FENCE` using `open_fence`:
 
 ```rust
-use self::nazar::t38::Types::{String};
-let work = |msg| {
-    println!("FENCE updates {:?}", msg);
-};
-n.open_fence("ws://127.0.0.1:9851", "my_fleet", "12.12", "33.22", "6000", work);
+fn action (out: &nazar::t38::NazarSender, msg: String) {
+    out.send("OK").unwrap();
+    println!("{}", msg);
+}
+
+//.....
+
+n.open_fence("ws://127.0.0.1:9851", "my_fleet", "12.12", "33.22", "6000", action);
 ```
 
 4) New API to execute T38 command - `cmd`, `arg` and `execute_with_args`. 
@@ -84,11 +87,14 @@ match n.execute_with_args() {
 5) New API to open a static geofence with GeoJSON object type. `open_fence_within`
 
  ```rust
-let n = nazar::t38::Client::new();
-let work = |msg| {
-    println!("FENCE updates {:?}", msg);
-};
-n.open_fence_within("ws://localhost:9851", "my_fleet", "qwerty123", vec![vec![12.32, 23.4], vec![22.32, 33.4], vec![42.32, 23.5], vec![12.32, 23.4]], work)
+fn action (out: &nazar::t38::NazarSender, msg: String) {
+    out.send("OK").unwrap();
+    println!("{}", msg);
+}
+
+//.....
+
+n.open_fence_within("ws://localhost:9851", "my_fleet", "qwerty123", vec![vec![12.32, 23.4], vec![22.32, 33.4], vec![42.32, 23.5], vec![12.32, 23.4]], action);
 ```