build: use solhint for linting

Author: abarmat

.solhint.json

@@ -0,0 +1,14 @@
+{
+  "extends": "solhint:recommended",
+  "plugins": ["prettier"],
+  "rules": {
+    "prettier/prettier": "error",
+    "func-visibility": ["warn", { "ignoreConstructors": true }],
+    "compiler-version": ["off"],
+    "constructor-syntax": "warn",
+    "quotes": ["error", "double"],
+    "reason-string": ["off"],
+    "not-rely-on-time": "off",
+    "no-empty-blocks": "off"
+  }
+}

.solhintignore

@@ -0,0 +1,9 @@
+node_modules
+
+./contracts/bancor
+./contracts/discovery/erc1056
+./contracts/rewards/RewardsManager.sol
+./contracts/staking/libs/LibFixedMath.sol
+./contracts/tests/RewardsManagerMock.sol
+./contracts/tests/ens
+./contracts/tests/testnet/GSRManager.sol

.soliumignore

@@ -55,7 +55,6 @@
     "eslint-plugin-promise": "^5.0.0",
     "eslint-plugin-standard": "^4.1.0",
     "ethereum-waffle": "^3.3.0",
-    "ethlint": "^1.2.5",
     "graphql-tag": "^2.12.4",
     "hardhat": "^2.2.0",
     "hardhat-abi-exporter": "^2.2.0",
@@ -72,6 +71,8 @@
     "p-queue": "^6.6.1",
     "prettier": "^2.2.1",
     "prettier-plugin-solidity": "^1.0.0-beta.9",
+    "solhint": "^3.3.6",
+    "solhint-plugin-prettier": "^0.0.5",
     "solidity-coverage": "^0.7.16",
     "ts-generator": "^0.1.1",
     "ts-node": "^9.1.1",
@@ -98,12 +99,12 @@
     "lint": "yarn lint:ts && yarn lint:sol",
     "lint:fix": "yarn lint:ts:fix && yarn lint:sol:fix",
     "lint:ts": "eslint '*/**/*.{js,ts}'",
-    "lint:ts:fix": "eslint '*/**/*.{js,ts}' --fix",
-    "lint:sol": "solium --dir ./contracts",
-    "lint:sol:fix": "solium --dir ./contracts --fix",
+    "lint:ts:fix": "prettier:ts && eslint '*/**/*.{js,ts}' --fix",
+    "lint:sol": "solhint './contracts/**/*.sol'",
+    "lint:sol:fix": "yarn prettier:sol && solhint --fix './contracts/**/*.sol'",
     "prettier": "yarn prettier:ts && yarn prettier:sol",
     "prettier:ts": "prettier --write 'test/**/*.ts'",
-    "prettier:sol": "prettier --write 'contracts/*.sol'",
+    "prettier:sol": "prettier --write 'contracts/**/*.sol'",
     "analyze": "scripts/analyze",
     "myth": "scripts/myth",
     "flatten": "scripts/flatten && scripts/clean",