Add all the A tasks

Task/Associative-array-Iteration/Go/associative-array-iteration.go

@@ -0,0 +1,19 @@
+myMap := map[string]int {
+	   "hello": 13,
+	   "world": 31,
+	   "!"    : 71 }
+
+// iterating over key-value pairs:
+for key, value := range myMap {
+    fmt.Printf("key = %s, value = %d\n", key, value)
+}
+
+// iterating over keys:
+for key := range myMap {
+    fmt.Printf("key = %s\n", key)
+}
+
+// iterating over values:
+for _, value := range myMap {
+    fmt.Printf("value = %d\n", value)
+}