Log Message:
Update miller to 2.1.1.

Changes:

v2.1.1

Incremental read-performance increase for CSV format

While #51 is still underway, already there is nearly a 2x
read-performance increase in v2.1.1 over v2.1.0.

v2.1.0

Minor enhancements and bug fixes

Highlights: travis-CI integration (thanks @SikhNerd!); hour-minute-second
functions; fixed pretty-print alignment of UTF-8 data.