Update sample QC demo notebook

[karenfeng]

What changes are proposed in this pull request?

The changes in #14 broke the sample QC demo notebook. This PR updates the notebook so that it functions as expected with the current version of Glow.

Addresses #132.

How is this patch tested?

• Unit tests
• Integration tests
• Manual tests

New notebook functions as expected.

[codecov]

Codecov Report

Merging #136 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #136      +/-   ##
==========================================
+ Coverage   94.77%   94.79%   +0.02%     
==========================================
  Files          82       82              
  Lines        3999     3999              
  Branches      382      382              
==========================================
+ Hits         3790     3791       +1     
+ Misses        209      208       -1

Impacted Files	Coverage Δ
...scala/io/projectglow/transformers/pipe/Piper.scala	95.38% <0%> (+1.53%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6c9e9cd...75444cb. Read the comment docs.