Fix in README.md example code

[ginovva320]

The Queue constructor requires a reference to the queue, not the tasks child. Fixed the code example given for the chat sanitization script.

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[coveralls]

Coverage remained the same at 100.0% when pulling 04bfb26fa5be2c14f63ac37b0b73fd5c88cb4004 on ginovva320:patch-1 into b11116fdcf6e37b30343a4927492be274e8c6051 on firebase:master.

[ginovva320]

I signed it!

[cbraynor]

Awesome, thanks for spotting that!