Fix typo in README.md

[franklsm1]

remove bad parameter in catch block

[coveralls]

Coverage remained the same at 100.0% when pulling b5e33ec on franklsm1:franklsm1-patch-1 into 1389cf7 on request:master.

[analog-nico]

Quick question because errors.TransformError is there by design:

• Do you think it is too confusing to use this Bluebird specific error filter here and we should remove it for this reason?
• Or is the code not working actually?

[franklsm1]

@analog-nico It actually works just confusing was all, but maybe that was just my co-worker and I trying to figure it out. For an example it just seemed easier to to stick with the standard catch block. Yes bluebird promises are used by rp, but normal promises do not allow those filters.

It was just a suggestion, and can be rejected if you see otherwise :)