Removed redundant unit tests.
Removed redundant unit tests.

Removed author info and last modified date from test_gate.py module.

Removed redundant unit tests for fc.gate.high_low(). Favored "inequality"
series of unit tests (unit tests which remove multiple high or low values
simultaneously, invoking the threshold functionality of fc.gate.high_low())
over the original tests (which only gated out the single highest and/or
lowest events).

See castillohair/fc#105.

taborlab/FlowCal,taborlab/FlowCal