toBeEqual( received, value, source ) {
      const pass = received === value;
      return expectReturn( pass,
        `[${ source }] expected ${ JSON.stringify( received ) } to equal ${ JSON.stringify( value ) }`,
        `[${ source }] expected ${ JSON.stringify( received ) } not to equal ${ JSON.stringify( value ) }` );
    }
Assert values equal
@param {String|Number|Boolean} received
@param {String|Number|Boolean} value
@param {String} source
@returns {Object}