Fixed MintableToken's initialize not being called.

contracts/token/ERC20/DetailedMintableToken.sol

@@ -7,6 +7,6 @@ import "./MintableToken.sol";
 contract DetailedMintableToken is Migratable, DetailedERC20, MintableToken {
   function initialize(address _sender, string _name, string _symbol, uint8 _decimals) isInitializer("DetailedMintableToken", "1.9.0-beta") {
     DetailedERC20.initialize(_name, _symbol, _decimals);
-    Ownable.initialize(_sender);
+    MintableToken.initialize(_sender);
   }
 }