test:replace indexOf, assert.equal, add mustCall()

replace indexOf with includes
replace assert.equal with assert.strictEqual
add common.mustCall
replace throw error with assert.ifError

PR-URL: https://github.com/nodejs/node/pull/8766


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>