Parsing markers/requirements fails with pyparsing 3.0.5

[9999years]

Pyparsing 3.0.5 changes the private API around originalTextFor, causing code in packaging that uses the private API to break:

packaging/packaging/requirements.py

Lines 69 to 72 in 8cb9dbf

	MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
	MARKER_EXPR.setParseAction(
	lambda s, l, t: Marker(s[t._original_start : t._original_end])
	)

This manifests as a failure in safety.

Reproduction:

from packaging.requirements import Requirement

Requirement('alabaster==0.7.12; python_version >= "3.6"\n')

The upstream issue is pyparsing/pyparsing#110 (comment)

[ptmcg]

Pyparsing 3.0.6 just released, implements warning suppression without changing results names.

May be moot in the face of other packaging PRs in progress, but should resolve some issues people are having with current packaging version and latest pyparsing.

Also utilizes run of packaging tests during TravisCI.