LG-570 Update typography scale to match spec

[gregory-casamento]

Why: The scale wasn't updated after the spec changed

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[jmhooper]

Looks like the sass linter caught you here

[gregory-casamento]

This was fixed. It was due to the 1.0 instead of 1. The linter wanted it to have no mantissa. This is corrected.

[gregory-casamento]

This should be ready for merge, pending a review.

[monfresh]

@gregory-casamento Could you please update the commit message so that the summary is on the first line, and the why and how are below? Also, could you please fix the SASS lint issue: https://codeclimate.com/github/18F/identity-idp/pull/2611 ?

[monfresh]

LGTM