fix decimals

contracts/external/ERC20/InitializableERC20.sol

@@ -13,7 +13,7 @@ contract InitializableERC20 {
     using SafeMath for uint256;
 
     string public name;
-    uint256 public decimals;
+    uint8 public decimals;
     string public symbol;
     uint256 public totalSupply;
 
@@ -30,7 +30,7 @@ contract InitializableERC20 {
         uint256 _totalSupply,
         string memory _name,
         string memory _symbol,
-        uint256 _decimals
+        uint8 _decimals
     ) public {
         require(!initialized, "TOKEN_INITIALIZED");
         initialized = true;

contracts/external/ERC20/InitializableMintableERC20.sol

@@ -14,7 +14,7 @@ contract InitializableMintableERC20 is InitializableOwnable {
     using SafeMath for uint256;
 
     string public name;
-    uint256 public decimals;
+    uint8 public decimals;
     string public symbol;
     uint256 public totalSupply;
 
@@ -31,7 +31,7 @@ contract InitializableMintableERC20 is InitializableOwnable {
         uint256 _initSupply,
         string memory _name,
         string memory _symbol,
-        uint256 _decimals
+        uint8 _decimals
     ) public {
         initOwner(_creator);
         name = _name;