WARN ajv-keywords@3.1.0 requires a peer of ajv@^6.0.0 but none is installed

[kenorb]

$ npm install
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN ajv-keywords@3.1.0 requires a peer of ajv@^6.0.0 but none is installed. You must install peer dependencies yourself.
npm WARN ansy@2.0.1 No repository field.
$ npm install ajv@^6.0.0
npm WARN ansy@2.0.1 No repository field.
+ ajv@6.4.0
$ npm install
npm WARN ansy@2.0.1 No repository field.
$ npm --version
5.6.0