update README.md

Author: theo-s68

MIGRATION.md

@@ -37,7 +37,7 @@ For Spot (Spot package):
     <dependency>
         <groupId>io.github.binance</groupId>
         <artifactId>binance-spot</artifactId>
-        <version>2.0.0</version>
+        <version>3.0.0</version>
     </dependency>
 ```
 

README.md

@@ -54,7 +54,7 @@ Each connector is published as a separate maven dependency. For example:
 <dependency>
   <groupId>io.github.binance</groupId>
   <artifactId>binance-spot</artifactId>
-  <version>2.0.0</version>
+  <version>3.0.0</version>
 </dependency>
 ```