Update ico-contract.sol

Author: tomterado

ico-contract.sol

@@ -19,19 +19,19 @@ pragma solidity ^0.4.18;
 // Safe maths
 // ----------------------------------------------------------------------------
 contract SafeMath {
-    function safeAdd(uint a, uint b) public pure returns (uint c) {
+    function safeAdd(uint a, uint b) internal pure returns (uint c) {
         c = a + b;
         require(c >= a);
     }
-    function safeSub(uint a, uint b) public pure returns (uint c) {
+    function safeSub(uint a, uint b) internal pure returns (uint c) {
         require(b <= a);
         c = a - b;
     }
-    function safeMul(uint a, uint b) public pure returns (uint c) {
+    function safeMul(uint a, uint b) internal pure returns (uint c) {
         c = a * b;
         require(a == 0 || c / a == b);
     }
-    function safeDiv(uint a, uint b) public pure returns (uint c) {
+    function safeDiv(uint a, uint b) internal pure returns (uint c) {
         require(b > 0);
         c = a / b;
     }