added linting to the contracts

contracts/erc20-bridge-sampler/contracts/src/DummyLiquidityProvider.sol

@@ -2,22 +2,20 @@ pragma solidity ^0.5.9;
 pragma experimental ABIEncoderV2;
 
 
-
 contract DummyLiquidityProvider
 {
     constructor()
         public
+    // solhint-disable-next-line no-empty-blocks
     {}
 
     /// @dev Quotes the amount of `makerToken` that would be obtained by
     ///      selling `sellAmount` of `takerToken`.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
     /// @param sellAmount Amount of `takerToken` to sell.
     /// @return makerTokenAmount Amount of `makerToken` that would be obtained.
     function getSellQuote(
-        address takerToken,
-        address makerToken,
+        address, /* takerToken */
+        address, /* makerToken */
         uint256 sellAmount
     )
         external
@@ -28,13 +26,11 @@ contract DummyLiquidityProvider
 
     /// @dev Quotes the amount of `takerToken` that would need to be sold in
     ///      order to obtain `buyAmount` of `makerToken`.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
     /// @param buyAmount Amount of `makerToken` to buy.
     /// @return takerTokenAmount Amount of `takerToken` that would need to be sold.
     function getBuyQuote(
-        address takerToken,
-        address makerToken,
+        address, /* takerToken */
+        address, /* makerToken */
         uint256 buyAmount
     )
         external

contracts/erc20-bridge-sampler/contracts/src/DummyLiquidityProviderRegistry.sol

@@ -8,6 +8,7 @@ contract DummyLiquidityProviderRegistry
 
     constructor()
         public
+    // solhint-disable-next-line no-empty-blocks
     {}
 
     mapping (address => mapping (address => address)) internal _gAddressBook;