feat(): readyNotice as function

[shmilky]

Support passing a method as a readyNotice that will be called instead of listening to text message

[coveralls]

Coverage decreased (-1.5%) to 96.316% when pulling bc10b12 on shmilky:master into 94334b0 on osher:master.

[osher]

mm. that gets to be lots of new code paths.

readme also needs updating.

please- change the merge target from master to readyNoticeFn
I'll add tests & readme there :)

[osher]

its fully compatible with prev versions.
Since this version starts with 0, by semver rules the minor is acting like a major and (~ and ^ behave the same)
leave version bumping to me

[osher]

replace lines 187 and 188 with:

        , " - readyNotice - optional string or a function,"
        , "    - string:  message to expect on service output that indicates the service is ready."
        , "    - function: is passed the usual err-1st callback to call when the service is ready, or to pass an error when such error occurs."
        , "       may also return a Promise instread"
        , "    default: the string '" + defaults.readyNotice + "'"

[osher]

not any function. an err-1st callback - hence callback.

[osher]

if ('string' == typeof ctx.readyNotice) {
    const readyNotice = ctx.readyNotice
    ctx.readyNotice = () => new Promise(done => child.stdout.on('data', (data) => ~data.indexOf(readyNotice) && done()))
}

var promise = ctx.readyNotice((err) => {
    if (!done) return
    if (!err) ctx.console.log('service started: %s', ctx.args.join(' '))
    done(err)
    done = null
})
promise && promise.then && promise.catch((err) => err || new Error('ready hook rejection')).then((err) => {
    done(err instasnceof Error ? err : null)
    done = null
})