function to change rawAsap.capacity value must be added

[zamuka]

When I handle thousands of promises at the same time I'm getting an error from asap module :
asap\asap.js:40
this.task.call();
^
TypeError: Cannot read property 'call' of null

If i increase the "capacity" value in rawAsap module - errors are gone.
So having a Function for changing asap capacity will be useful.

[kriskowal]

The capacity should be adaptive. Thank you for reporting. If you have a chance to write a test that reproduces the problem, I’d be grateful.

[Macil]

This is a duplicate of #55 which was fixed.

[rkatic]

As @agentme already noted, this seems duplicate of #55.