Switch Kotlin version to 1.1.3, remove obsolete Gradle syntax (#707)

common/build.gradle

@@ -30,6 +30,8 @@ task build {
     dependsOn "${host}Hash"
 }
 
-task clean << {
+task clean {
-    delete buildDir
+    doLast {
+        delete buildDir
+    }
 }

gradle.properties

@@ -14,7 +14,7 @@
 # limitations under the License.
 #
 
-kotlin_version=1.1.0
+kotlin_version=1.1.3
 llvmVersion = 3.9.0
 remoteRoot=konan_tests
 #kotlinCompilerModule=org.jetbrains.kotlin:kotlin-compiler:1.1-SNAPSHOT

runtime/build.gradle

@@ -45,6 +45,8 @@ targetList.each { targetName ->
 
 task hostRuntime(dependsOn: "${rootProject.ext.host}Runtime")
 
-task clean << {
+task clean {
-    delete buildDir
+    doLast {
+        delete buildDir
+    }
 }