Hacking Session, Day 1

Stuff worked on during the hacking session on day 1:

• cal@: Fix maintainer timeout handling in pull request bot due to a query being sent to the wrong database (​https://github.com/macports/mpbot-github/commit/515a0640ec06a68ff73221503556d60f55e8128d)
• l2dy@: Fix a couple of corner cases in maintainer detection for Portfiles in pull request bot (​https://github.com/macports/mpbot-github/commit/09f640ceb50e730a9ccbfb91e71ecc726a15036e)
• l2dy@: Enable maintainer timeout handling on openmaintainer ports in pull request bot (​https://github.com/macports/mpbot-github/commit/7805a25a28249468effdd43bc0dab365324bd9c0)
• l2dy@: Fix Travis CI builds for pull requests on 10.13 by building the MacPorts package required (​https://github.com/macports/macports-base/commit/e8447960aad1ef6b97ce910e642cf79cc969aa04) and working around a bug in bintray deployment in Travis (​https://github.com/macports/macports-base/commit/68eb49981864b4d470c6d37ca632f454a1ead35b, ​https://github.com/travis-ci/travis-ci/issues/9314)
• cal@: Improve documentation of mpbb (​https://github.com/macports/mpbb/commit/6dd94d367b768580071e75ebc4a3d8911e1ad517, ​https://github.com/macports/mpbb/commit/f64c0dacaff29b6561262032eec3d116b0ee8802)
• umeshksingla@: Fix a crash in variant handling in port migrate (​https://github.com/macports/macports-base/commit/272ae31859ae566fb3ee6372431c76396e171437)
• raimue@: Push build status to commit log on GitHub to make it easier to find builds for a certain commit (​https://github.com/macports/macports-infrastructure/commit/ff18166be63a5a6ad7b67be82c4b06c2a281da88, ​https://github.com/macports/macports-infrastructure/commit/d9aeeb32b22a06eb39f1a0317869e9c12e3ed021)
• raimue@: Remove misleading patchfile naming examples from the guide (​https://github.com/macports/macports-guide/commit/8690d0f287f8c03d51404147dac6d54503a401c2)