updated README with prerequisites

README.md

@@ -5,3 +5,8 @@
 This is the companion code to my eBook [Get Your Hands Dirty on Clean Architecture](https://leanpub.com/get-your-hands-dirty-on-clean-architecture).
 
 It implements a domain-centric "Hexagonal" approach of a common web application with Java and Spring Boot. 
+
+## Prerequisites
+
+* JDK 8
+* this project uses Lombok, so enable annotation processing in your IDE

build.gradle

@@ -21,4 +21,9 @@ subprojects {
         }
     }
 
+    compileJava {
+        sourceCompatibility = 1.8
+        targetCompatibility = 1.8
+    }
+
 }