Merge pull request #119 from kategory/fix-build-android-4.x

fix usage on android API <19

Author: pakoito

kategory/src/main/kotlin/kategory/typeclasses/Typeclass.kt

@@ -3,7 +3,6 @@ package kategory
 import java.lang.reflect.ParameterizedType
 import java.lang.reflect.Type
 import java.util.Arrays
-import java.util.Objects
 import java.util.concurrent.ConcurrentHashMap
 
 /**
@@ -62,8 +61,8 @@ class InstanceParametrizedType(val raw: Type, val typeArgs: List<Type>) : Parame
 
     override fun hashCode(): Int {
         return Arrays.hashCode(actualTypeArguments) xor
-                Objects.hashCode(ownerType) xor
-                Objects.hashCode(rawType)
+                hashCode(ownerType) xor
+                hashCode(rawType)
     }
 
     override fun toString(): String {
@@ -102,6 +101,10 @@ class InstanceParametrizedType(val raw: Type, val typeArgs: List<Type>) : Parame
         return sb.toString()
     }
 
+    fun hashCode(o: Any?): Int {
+        return o?.hashCode() ?: 0
+    }
+
 }
 
 /**