Remove codecov.io, coveralls, eslint for now

Given that eslint is adding TypeScript support, we can migrate back to
ESLint in the future.

packages/ripple-address-codec/.gitignore

@@ -59,5 +59,3 @@ out/
 
 # Ignore perf test cache
 scripts/cache
-
-eslintrc

packages/ripple-address-codec/package.json

@@ -19,10 +19,6 @@
   },
   "devDependencies": {
     "@types/node": "^10.12.0",
-    "codecov.io": "^0.1.6",
-    "coveralls": "~2.11.4",
-    "eslint": "^4.19.1",
-    "eslint-plugin-no-unused-expressions": "^0.1.0",
     "mocha": "^5.0.5",
     "tslint": "^5.11.0",
     "tslint-eslint-rules": "^5.4.0",

packages/ripple-address-codec/test/codec-test.js

@@ -1,7 +1,3 @@
-/* eslint-disable no-unused-expressions/no-unused-expressions */
-
-'use strict'
-
 const assert = require('assert')
 const api = require('../dist')
 

packages/ripple-address-codec/test/xrp-codec-test.js

@@ -1,7 +1,3 @@
-/* eslint-disable no-unused-expressions/no-unused-expressions */
-
-'use strict'
-
 const assert = require('assert')
 const api = require('../dist/xrp-codec')