Move ERC20 contracts to ERC20 custom folder (#701)

* Move ERC20 contracts to ERC20 custom folder

* Fix linter warnings for ERC20 contracts

contracts/crowdsale/Crowdsale.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.18;
 
-import "../token/MintableToken.sol";
+import "../token/ERC20/MintableToken.sol";
 import "../math/SafeMath.sol";
 
 

contracts/examples/SampleCrowdsale.sol

@@ -2,7 +2,7 @@ pragma solidity ^0.4.18;
 
 import "../crowdsale/CappedCrowdsale.sol";
 import "../crowdsale/RefundableCrowdsale.sol";
-import "../token/MintableToken.sol";
+import "../token/ERC20/MintableToken.sol";
 
 
 /**

contracts/examples/SimpleToken.sol

@@ -1,7 +1,7 @@
 pragma solidity ^0.4.18;
 
 
-import "../token/StandardToken.sol";
+import "../token/ERC20/StandardToken.sol";
 
 
 /**

contracts/mocks/BasicTokenMock.sol

@@ -1,7 +1,7 @@
 pragma solidity ^0.4.18;
 
 
-import "../token/BasicToken.sol";
+import "../token/ERC20/BasicToken.sol";
 
 
 // mock class using BasicToken

contracts/mocks/BurnableTokenMock.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.18;
 
-import "../token/BurnableToken.sol";
+import "../token/ERC20/BurnableToken.sol";
 
 
 contract BurnableTokenMock is BurnableToken {

contracts/mocks/DetailedERC20Mock.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.18;
 
-import "../token/StandardToken.sol";
+import "../token/ERC20/StandardToken.sol";
 import "../token/ERC20/DetailedERC20.sol";
 
 

contracts/mocks/ERC223TokenMock.sol

@@ -1,8 +1,6 @@
 pragma solidity ^0.4.18;
 
-
+import "../token/ERC20/BasicToken.sol";
-import "../token/BasicToken.sol";
-
 
 contract ERC223ContractInterface {
   function tokenFallback(address _from, uint256 _value, bytes _data) external;

contracts/mocks/PausableTokenMock.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.18;
 
-import "../token/PausableToken.sol";
+import "../token/ERC20/PausableToken.sol";
 
 
 // mock class using PausableToken

contracts/mocks/StandardTokenMock.sol

@@ -1,8 +1,6 @@
 pragma solidity ^0.4.18;
 
-
+import "../token/ERC20/StandardToken.sol";
-import "../token/StandardToken.sol";
-
 
 // mock class using StandardToken
 contract StandardTokenMock is StandardToken {

contracts/token/ERC20/BasicToken.sol

@@ -1,8 +1,8 @@
 pragma solidity ^0.4.18;
 
 
-import "./ERC20/ERC20Basic.sol";
+import "./ERC20Basic.sol";
-import "../math/SafeMath.sol";
+import "../../math/SafeMath.sol";
 
 
 /**

contracts/token/ERC20/CappedToken.sol

@@ -7,7 +7,6 @@ import "./MintableToken.sol";
  * @title Capped token
  * @dev Mintable token with a token cap.
  */
-
 contract CappedToken is MintableToken {
 
   uint256 public cap;

contracts/token/ERC20/ERC20.sol

@@ -1,6 +1,5 @@
 pragma solidity ^0.4.18;
 
-
 import "./ERC20Basic.sol";
 
 

contracts/token/ERC20/MintableToken.sol

@@ -1,9 +1,7 @@
 pragma solidity ^0.4.18;
 
-
 import "./StandardToken.sol";
-import "../ownership/Ownable.sol";
+import "../../ownership/Ownable.sol";
-
 
 
 /**
@@ -12,7 +10,6 @@ import "../ownership/Ownable.sol";
  * @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120
  * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
  */
-
 contract MintableToken is StandardToken, Ownable {
   event Mint(address indexed to, uint256 amount);
   event MintFinished();

contracts/token/ERC20/PausableToken.sol

@@ -1,12 +1,11 @@
 pragma solidity ^0.4.18;
 
 import "./StandardToken.sol";
-import "../lifecycle/Pausable.sol";
+import "../../lifecycle/Pausable.sol";
 
 
 /**
  * @title Pausable token
- *
  * @dev StandardToken modified with pausable transfers.
  **/
 contract PausableToken is StandardToken, Pausable {

contracts/token/ERC20/StandardToken.sol

@@ -1,8 +1,7 @@
 pragma solidity ^0.4.18;
 
-
 import "./BasicToken.sol";
-import "./ERC20/ERC20.sol";
+import "./ERC20.sol";
 
 
 /**

contracts/token/ERC20/TokenTimelock.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.18;
 
-import "./ERC20/SafeERC20.sol";
+import "./SafeERC20.sol";
 
 
 /**

contracts/token/ERC20/TokenVesting.sol

@@ -1,9 +1,9 @@
 pragma solidity ^0.4.18;
 
-import "./ERC20/ERC20Basic.sol";
+import "./ERC20Basic.sol";
-import "./ERC20/SafeERC20.sol";
+import "./SafeERC20.sol";
-import "../ownership/Ownable.sol";
+import "../../ownership/Ownable.sol";
-import "../math/SafeMath.sol";
+import "../../math/SafeMath.sol";
 
 
 /**

contracts/token/ERC827/ERC827Token.sol

@@ -1,7 +1,7 @@
 pragma solidity ^0.4.13;
 
 import "./ERC827.sol";
-import "../StandardToken.sol";
+import "../ERC20/StandardToken.sol";
 
 /**
    @title ERC827, an extension of ERC20 token standard