Fix remaining revert reasons.

contracts/token/ERC721/ERC721.sol

@@ -86,7 +86,7 @@ contract ERC721 is ERC165, IERC721 {
      */
     function approve(address to, uint256 tokenId) public {
         address owner = ownerOf(tokenId);
-        require(to != owner, "ERC721: transfer to current owner");
+        require(to != owner, "ERC721: approval to current owner");
 
         require(msg.sender == owner || isApprovedForAll(owner, msg.sender),
             "ERC721: approve caller is not owner nor approved for all"

test/token/ERC20/behaviors/ERC20Capped.behavior.js

@@ -15,12 +15,12 @@ function shouldBehaveLikeERC20Capped (minter, [other], cap) {
 
     it('should fail to mint if the amount exceeds the cap', async function () {
       await this.token.mint(other, cap.subn(1), { from });
-      await shouldFail.reverting.withMessage(this.token.mint(other, 2, { from }));
+      await shouldFail.reverting.withMessage(this.token.mint(other, 2, { from }), 'ERC20Capped: cap exceeded');
     });
 
     it('should fail to mint after cap is reached', async function () {
       await this.token.mint(other, cap, { from });
-      await shouldFail.reverting.withMessage(this.token.mint(other, 1, { from }));
+      await shouldFail.reverting.withMessage(this.token.mint(other, 1, { from }), 'ERC20Capped: cap exceeded');
     });
   });
 }

test/token/ERC721/ERC721.behavior.js

@@ -315,9 +315,8 @@ function shouldBehaveLikeERC721 (
         describe('to a contract that does not implement the required function', function () {
           it('reverts', async function () {
             const invalidReceiver = this.token;
-            await shouldFail.reverting.withMessage(
-              this.token.safeTransferFrom(owner, invalidReceiver.address, tokenId, { from: owner }),
-              'VM Exception while processing transaction: revert'
+            await shouldFail.reverting(
+              this.token.safeTransferFrom(owner, invalidReceiver.address, tokenId, { from: owner })
             );
           });
         });
@@ -406,7 +405,7 @@ function shouldBehaveLikeERC721 (
       context('when the address that receives the approval is the owner', function () {
         it('reverts', async function () {
           await shouldFail.reverting.withMessage(
-            this.token.approve(owner, tokenId, { from: owner }), 'ERC721: transfer to current owner'
+            this.token.approve(owner, tokenId, { from: owner }), 'ERC721: approval to current owner'
           );
         });
       });