chore(): update eslint, run lint only on latest lts

.travis.yml

@@ -57,6 +57,12 @@ matrix:
       addons:
         postgresql: '9.6'
 
+    # only run lint on latest Node LTS
+    - node_js: lts/*
+      addons:
+        postgresql: '9.6'
+      script: yarn lint
+
     # PostgreSQL 9.2 only works on precise
     - node_js: lts/carbon
       addons:

.yarnrc

@@ -0,0 +1 @@
+--install.ignore-engines true

package.json

@@ -10,22 +10,20 @@
     "packages/*"
   ],
   "scripts": {
-    "test": "yarn lint && yarn lerna exec yarn test",
+    "test": "yarn lerna exec yarn test",
     "build": "yarn lerna exec --scope pg-protocol yarn build",
     "pretest": "yarn build",
-    "lint": "if [ -x ./node_modules/.bin/prettier ]; then eslint '*/**/*.{js,ts,tsx}'; fi;"
+    "lint": "eslint '*/**/*.{js,ts,tsx}'"
   },
   "devDependencies": {
-    "@typescript-eslint/eslint-plugin": "^2.27.0",
-    "@typescript-eslint/parser": "^2.27.0",
-    "eslint": "^6.8.0",
-    "eslint-config-prettier": "^6.10.1",
+    "@typescript-eslint/eslint-plugin": "^4.4.0",
+    "@typescript-eslint/parser": "^4.4.0",
+    "eslint": "^7.11.0",
+    "eslint-config-prettier": "^6.12.0",
     "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-prettier": "^3.1.2",
-    "lerna": "^3.19.0"
-  },
-  "optionalDependencies": {
-    "prettier": "2.0.4"
+    "eslint-plugin-prettier": "^3.1.4",
+    "lerna": "^3.19.0",
+    "prettier": "2.1.2"
   },
   "prettier": {
     "semi": false,