Merge branch 'v2-prototype' into fix/five_decimal_scenario

* v2-prototype: (75 commits)
  Update relayer grid tiles to use Text
  Fix build
  Update file structure
  Update 2.0.0 artifacts
  Move ledgerhq module declarations to typescript-typings
  Export LedgerEthereumClient type in subproviders
  Update artifacts
  Add logging and updated artifacts
  Fix migrations
  Run prettier
  Add Kovan artifacts
  Use ledger subprovider
  Add Kovan migrations
  Remove state variable from Link component in Portal
  Make registerAssetProxy append only
  Update staging api link
  Change getTransactionReceipt to awaitTransactionMined
  Move /docs route to the end
  Remove extra call to scrollIntoView for wallet in onboarding
  Update expectRevertReasonOrAlwaysFailingTransactionAsync to check status codes
  ...

1 files changed, 73 insertions, 0 deletions

diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
new file mode 100644
index 000000000..eb879b6a8
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
@@ -0,0 +1,73 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+contract IERC20Token {
+
+    /// @notice send `value` token to `to` from `msg.sender`
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transfer(address _to, uint256 _value)
+        public
+        returns (bool);
+
+    /// @notice send `value` token to `to` from `from` on the condition it is approved by `from`
+    /// @param _from The address of the sender
+    /// @param _to The address of the recipient
+    /// @param _value The amount of token to be transferred
+    /// @return Whether the transfer was successful or not
+    function transferFrom(address _from, address _to, uint256 _value)
+        public
+        returns (bool);
+    
+    /// @notice `msg.sender` approves `_spender` to spend `_value` tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @param _value The amount of wei to be approved for transfer
+    /// @return Whether the approval was successful or not
+    function approve(address _spender, uint256 _value)
+        public
+        returns (bool);
+
+    /// @param _owner The address from which the balance will be retrieved
+    /// @return The balance
+    function balanceOf(address _owner)
+        public view
+        returns (uint256);
+
+    /// @param _owner The address of the account owning tokens
+    /// @param _spender The address of the account able to transfer the tokens
+    /// @return Amount of remaining tokens allowed to spent
+    function allowance(address _owner, address _spender)
+        public view
+        returns (uint256);
+
+    event Transfer(
+        address indexed _from,
+        address indexed _to,
+        uint256 _value
+    );
+    
+    event Approval(
+        address indexed _owner,
+        address indexed _spender,
+        uint256 _value
+    );
+}