Added cache limit

[TwoAbove]

This PR adds a cache limiter.

This is something that we need to keep the cache from growing too large if we have a spike in caching.

[TwoAbove]

I'm not sure what's wrong with the CI, though. It seems that It's passing and then returning 1?

[ReneKroon]

Hi there, i will probably merge this later this week.

The CI is fine, however i've included some token for the code coverage. I should only trigger that on my own account i suppose.

[TwoAbove]

Thanks @ReneKroon !

[ReneKroon]

One note, the test does'nt check that indeed the last added items are in the cache. Can you fix that? I have no other comments and will merge after checking the build status manually (i'll accept that Travis cannot work with remote MR's at this time and fix that later)

[TwoAbove]

@ReneKroon sure, I'll add more tests

[TwoAbove]

@ReneKroon Updated the test to assert that only the last 10 are present

[ReneKroon]

merging, will release this week as well.

[TwoAbove]

@ReneKroon Thank you!

[ReneKroon]

released as v2.1.0