Draws more attention to recurrence rule default values.

[martellaj]

This is a very minor patch to the README, spurred from my own experience with missing the affected line when making a recurrence rule. My update just draws more attention to that last bit where you explain that if you don't explicitly set the minute value to 0, the job will be executed every minute of the hour.

[martellaj]

Looks like y'all have merged some bad code into here. I only touched the README and your CI build broke.

[santigimeno]

The tests are fine. It's just the test coverage step failing. Not a big deal. Thanks for the contribution

[santigimeno]

@tejasmanohar The issue with Travis seems related with the Coveralls configuration. I've no experience with it, could you check it? Thanks! Link: https://travis-ci.org/node-schedule/node-schedule/builds/107028308

[tejasmanohar]

Hm, coverrals won't show node-schedule/node-schedule in the available sources for me to set for the project. I will look more into it this evening & contact support if necessary :)