JSON schema util

This is a utility to validate data against a JSON schema.

example

``js
const {validate} = require('json-schema-util');

// set a json schema
const schema = {
type: "object",
properties: {
testNum: {
type: "number"
},
testString: {
type: "string"
}
}
};
`

Validation success:
`js
const data = { testNum: 1 };
const res = validate(data, schema);

console.log(res.isValid) // true
`

Validation error:
`js
const data = { testNum: 'a', testString: 1 };
const res = validate(data, schema);

console.log(res.isValid) // false
console.log(res.errors) // {isValid: false, errors: {{ value: 'a', property: 'tesnNum', message: '...'}}};

``