Update httplib2 requirement from <0.18.2 to <0.19.1

[dependabot]

Updates the requirements on httplib2 to permit the latest version.

Changelog

Sourced from httplib2's changelog.

0.19.0

auth: parse headers using pyparsing instead of regexp httplib2/httplib2#182

auth: WSSE token needs to be string not bytes httplib2/httplib2#179

0.18.1

explicit build-backend workaround for pip build isolation bug "AttributeError: 'module' object has no attribute 'legacy'" on pip install httplib2/httplib2#169

0.18.0

IMPORTANT security vulnerability CWE-93 CRLF injection Force %xx quote of space, CR, LF characters in uri. Special thanks to Recar https://github.com/Ciyfly for discrete notification. https://cwe.mitre.org/data/definitions/93.html

0.17.4

Ship test suite in source dist httplib2/httplib2#168

0.17.3

IronPython2.7: relative import iri2uri fixes ImportError httplib2/httplib2#163

0.17.2

python3 + debug + IPv6 disabled: https raised "IndexError: Replacement index 1 out of range for positional args tuple" httplib2/httplib2#161

0.17.1

python3: no_proxy was not checked with https httplib2/httplib2#160

0.17.0

feature: Http().redirect_codes set, works after follow(_all)_redirects check This allows one line workaround for old gcloud library that uses 308 response without redirect semantics. httplib2/httplib2#156

0.16.0

... (truncated)

Commits

• 81e80d0 v0.19.0 release
• c3aed1e fix release script, interactive part
• bd9ee25 parse auth headers using pyparsing instead of regexp
• 33090ab initial fuzz testing integration with OSS-Fuzz
• 595e248 auth: WSSE token needs to be string not bytes
• 9bf300c v0.18.1 release
• cb2940a explicit build-backend workaround pip build isolation bug 6264
• 94f48ef check-manifest build tool
• 828c26d Security Policy
• 8373177 v0.18.0 release
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually