Use released version in README and demos

Author: neiser

README.md

@@ -36,7 +36,7 @@ Inside your Spring Boot application, add the following (maven) dependency:
 <dependency>
     <groupId>de.qaware.tools.openapi-generator-for-spring</groupId>
     <artifactId>openapi-generator-for-spring-starter</artifactId>
-    <version>3.0.0</version>
+    <version>4.0.0</version>
 </dependency>
 ```
 

demo/openapi-generator-for-spring-demo-webflux/pom.xml

@@ -27,7 +27,7 @@
         <dependency>
             <groupId>de.qaware.tools.openapi-generator-for-spring</groupId>
             <artifactId>openapi-generator-for-spring-starter</artifactId>
-            <version>3.0.0</version>
+            <version>4.0.0</version>
         </dependency>
     </dependencies>
 

demo/openapi-generator-for-spring-demo-webmvc/pom.xml

@@ -40,7 +40,7 @@
         <dependency>
             <groupId>de.qaware.tools.openapi-generator-for-spring</groupId>
             <artifactId>openapi-generator-for-spring-starter</artifactId>
-            <version>3.0.0</version>
+            <version>4.0.0</version>
             <!-- The library works without YAML -->
             <exclusions>
                 <exclusion>