Update build.gradle

Author: jleetutorial

build.gradle

@@ -9,12 +9,22 @@ repositories {
     mavenCentral()
 }
 
+idea {
+    project {
+        jdkName = '1.8'
+        languageLevel = '1.8'
+    }
+}
+
 dependencies {
     compile group: 'org.apache.spark', name: 'spark-core_2.10', version: '2.1.0'
     compile group: 'org.apache.spark', name: 'spark-sql_2.10', version: '2.1.0'
     compile group: 'org.scala-lang', name: 'scala-library', version: '2.10.6'
 }
 
+compileScala.targetCompatibility = "1.8"
+compileScala.sourceCompatibility = "1.8"
+
 
 jar {
     zip64 true