fix Api::MAX_ID_LENGTH
fix Api::MAX_ID_LENGTH

it was being too conservative. there can actually be 19 digit IDs,
they just can't be greater than 2^63 - 1. Which we really don't care
to verify with a regex ... ruby properly parses and serializes those
into a Bignum, and postgres doesn't puke on the oversized ID, just
correctly returns no matching result.

Change-Id: Ic1f8d2e1355c6b61468e4494e68afc4c6db39434
Reviewed-on: https://gerrit.instructure.com/103100
Tested-by: Jenkins
Reviewed-by: Rob Orton <7e09c9d3e96378bf549fc283fd6e1e5b7014cc33@instructure.com>
Product-Review: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>
QA-Review: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>

sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,djbender/canvas-lms