Remove duplicate configuration for compatibility

complete/build.gradle

@@ -23,9 +23,6 @@ repositories {
     mavenCentral()
 }
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
-
 dependencies {
     compile("org.springframework.boot:spring-boot-starter-websocket")
     compile("org.springframework:spring-messaging")

initial/build.gradle

@@ -23,9 +23,6 @@ repositories {
     mavenCentral()
 }
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
-
 dependencies {
     compile("org.springframework.boot:spring-boot-starter-websocket")
     compile("org.springframework:spring-messaging")