Limit spotless checks to java classes in expected java dirs (#1490)

Sometimes build generated classes (like JMH) get caught up in IntelliJ's build dirs and the formatter doesn't like that. Change the spotless filter to only examine files in their expected dirs.
Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

build.gradle

@@ -105,7 +105,7 @@ allprojects {
     java {
       // This path needs to be relative to each project
       target fileTree('.') {
-        include '**/*.java'
+        include '**/src/*/java/**/*.java'
         exclude '**/generalstate/GeneralStateReferenceTest*.java'
         exclude '**/generalstate/GeneralStateRegressionReferenceTest*.java'
         exclude '**/blockchain/BlockchainReferenceTest*.java'
@@ -128,7 +128,7 @@ allprojects {
 
     // Below this line are currently only license header tasks
     format 'groovy', {
-      target '**/*.groovy'
+      target '**/src/*/grovy/**/*.groovy'
       licenseHeaderFile "${rootDir}/gradle/spotless.java.license", 'import'
     }