Add ability for Review Bot tools to attach logs

Review Request #10318 — Created Nov. 8, 2018 and discarded — Latest diff uploaded




Allows Review Bot tools to attach their console output to Status Updates.

Adds ability to attach output files to checkstyle, Cppcheck, CppLint, doc8,
flake8, JSHint, PMD, pycodestyle, pydocstyle, and pyflakes.

Adds an option to the above-mentioned Review Bot tools to attach the output
files. The default is set to not attach files.

Tested ability to attach log files by configuring integrations with the
Review Bot tools, running each tool, and examining the attachments.