Effects: Warn and fill jQuery.fx.interval

[dmethvin]

Fixes #215

[mention-bot]

@dmethvin, thanks for your PR! By analyzing the annotation information on this pull request, we identified @markelog, @mgol and @silentroach to be potential reviewers

[coveralls]

Coverage decreased (-1.05%) to 87.5% when pulling a2df588 on dmethvin:dp-fxinterval into 6041d46 on jquery:master.

[mgol]

LGTM.

[mgol]

Or maybe we could add a test ensuring no warnings happen for browsers not having rAF?

[coveralls]

Coverage decreased (-1.05%) to 87.5% when pulling 8551ddc on dmethvin:dp-fxinterval into 6041d46 on jquery:master.

[dmethvin]

I refactored the tests a bit to assert that non-rAF browsers don't warn. Coverage decreases since the tests are conditioned on the presence of rAF. I checked manually on IE9 and Android and it reports correctly.