FIX: pyparsing 3.0 support

[richardotis]

Fixes gh-347, which reports a regression with the pyparsing 3.0 pre-release. This change should be backwards compatible with pyparsing 2.4+. I do not know the precise root cause of the regression, as I was able to narrow the problem down empirically. My best guess is that the semantics of pyparsing.White() have changed in some way.

@bocklund This should be run against your private collection of TDBs to identify regressions.

Checklist

• If any dependencies have changed, the changes are reflected in the
  • setup.py
  • environment-dev.yml

[codecov]

Codecov Report

Merging #348 (48b340b) into develop (2e79f0f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #348   +/-   ##
========================================
  Coverage    89.75%   89.75%           
========================================
  Files           44       44           
  Lines         4275     4275           
========================================
  Hits          3837     3837           
  Misses         438      438           

Impacted Files	Coverage Δ
pycalphad/io/tdb.py	87.62% <ø> (ø)

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[bocklund]

I’ll try to get the pre-release installed tomorrow and test against the databases I have.

[bocklund]

I compared 3.0.0b2 to 2.4.7 locally and there were no regressions across 522 databases.