Addressing the linear growth of the reward rate

packages/kosu-system-contracts/contracts/validator/ValidatorRegistry.sol

@@ -64,7 +64,7 @@ contract ValidatorRegistry {
     uint public nextChallenge = 1;
     bytes32[] public _listingKeys;
     EventEmitter private eventEmitter;
-    uint _maxGenerationSum = 2 ether * 2 ether;
+    uint _maxGenerationSum = 2 ether;
 
     /** @dev Create a new ValidatorRegistry implementation
         @notice Create a new ValidatorRegistry implementation
@@ -103,7 +103,7 @@ contract ValidatorRegistry {
         @return Maximum KosuToken a validator can generate per period.
     */
     function maxRewardRate() public view returns (uint) {
-        return (sqrt(_maxGenerationSum));
+        return _maxGenerationSum;
     }
 
     /** @dev Expose listing data for given public key.
@@ -406,7 +406,7 @@ contract ValidatorRegistry {
         } else {
             if (listing.rewardRate > 0) {
                 uint rewardRate = uint(listing.rewardRate);
-                _maxGenerationSum = _maxGenerationSum.add(rewardRate.mul(rewardRate));
+                _maxGenerationSum = _maxGenerationSum.add(sqrt(rewardRate));
             }
 
             listing.lastRewardBlock = block.number;
@@ -555,7 +555,7 @@ contract ValidatorRegistry {
     function removeListing(Listing storage l) internal {
         if (l.rewardRate > 0 && l.confirmationBlock > 0) {
             uint rewardRate = uint(l.rewardRate);
-            _maxGenerationSum = _maxGenerationSum.sub(rewardRate.mul(rewardRate));
+            _maxGenerationSum = _maxGenerationSum.sub(sqrt(rewardRate));
         }
 
         bytes32[] memory data = new bytes32[](1);

packages/kosu-system-contracts/package.json

@@ -13,7 +13,7 @@
         "url": "https://github.com/ParadigmFoundation/kosu-monorepo/issues"
     },
     "scripts": {
-        "test": "ts-mocha -p test/tsconfig.json test/* --timeout 0 --slow 2000",
+        "test": "yarn build && ts-mocha -p test/tsconfig.json test/* --timeout 0 --slow 2000",
         "contracts:test:ci": "ts-mocha -p test/tsconfig.json test/* --slow 2000 --timeout 0 -b -- geth",
         "coverage": "ts-mocha -p test/tsconfig.json test/* --slow 2000 --timeout 100000 -- runCoverage && istanbul report html && open coverage/index.html",
         "build": "run-s compile:solidity generate_contract_wrappers compile:typescript",