Adds failing test for not-yet-reached keyframe calculation.
Makes newly-added fill-in test pass.

Updates old, related test to not expect a null value.
Builds 1.2.1 binaries.
First-pass fix for broken single-keyframe behavior.
Updates failing tests.
Removes an unnecessary condition check.
Removes null check.
Revs and builds 1.3.0.
Merge pull request #1 from jeremyckahn/bugfix/undefined-early-keyframes

Bugfix — Undefined early keyframes