chore: add test coverage on protocol getter

Coverage droppned while refactoring. As currently the value of 'MVP()' is not used.
We only check protocol != More_VP() now. This commit add test to bring up the coverage.

plasma_framework/contracts/mocks/framework/ProtocolWrapper.sol

@@ -3,6 +3,16 @@ pragma solidity 0.5.11;
 import "../../src/framework/Protocol.sol";
 
 contract ProtocolWrapper {
+    // solhint-disable-next-line func-name-mixedcase
+    function MVP() public pure returns (uint8) {
+        return Protocol.MVP();
+    }
+
+    // solhint-disable-next-line func-name-mixedcase
+    function MORE_VP() public pure returns (uint8) {
+        return Protocol.MORE_VP();
+    }
+
     function isValidProtocol(uint8 protocol) public pure returns (bool) {
         return Protocol.isValidProtocol(protocol);
     }

plasma_framework/test/src/framework/Protocol.test.js

@@ -1,14 +1,27 @@
 const Protocol = artifacts.require('ProtocolWrapper');
 
+const { BN } = require('openzeppelin-test-helpers');
 const { expect } = require('chai');
 
 const { PROTOCOL } = require('../../helpers/constants.js');
 
-contract('Protocol', () => {
+contract.only('Protocol', () => {
     before(async () => {
         this.test = await Protocol.new();
     });
 
+    describe('MORE_VP()', () => {
+        it('should return protocol value of MoreVP', async () => {
+            expect(await this.test.MORE_VP()).to.be.bignumber.equal(new BN(PROTOCOL.MORE_VP));
+        });
+    });
+
+    describe('MVP()', () => {
+        it('should return protocol value of MVP', async () => {
+            expect(await this.test.MVP()).to.be.bignumber.equal(new BN(PROTOCOL.MVP));
+        });
+    });
+
     describe('isValidProtocol', () => {
         it('should return true for MVP protocol', async () => {
             expect(await this.test.isValidProtocol(PROTOCOL.MVP)).to.be.true;