textproc/py-elasticsearch5: Unpin urllib3 version

[koobs]

Summary

textproc/py-elasticsearch5: Unpin urllib3 version

elasticsearch5 is a dependent of net/urllib3, which needs to be updated, and is
the last dependent that pins (maximally) its urllib3 dependency.

This change backports an upstream commit to unpin the urllib3 version, and adds
TEST_DEPENDS and a (do-)test target to improve QA substantially.

 - Switch to GitHub: test files not packaged in sdist. Use GH_TAGNAME to use
   hash from the 5.5.x branch so as to keep the same internal package name and
   include a comment in port as to why to prevent mistakes when updating the
   version later whilst using GitHub sources.
 - Pet portlint ("USES" has to appear earlier.)

PR: 229322 [1]
Reviewed_by: ?? (elastic@)
Approved by: portmgr (blanket: framework compliance/support)
MFH: 2019Q1

This change will need to be MFH'd because the urllib3 update will be MFH'd due
to a security vulnerability.

Test Plan

• portlint: OK (looks fine.)
• testport: OK (poudriere: 112amd64, py27, py37)
• maketest: OK (Ran 103 tests in 13.097s OK (SKIP=1). Note: no live ES server tests)

[koobs]

Replace 'elasticache' typo with 'elasticsearch'

[koobs]

Committed in rP499073