Fix: properly check travis-ci.com 'green' status (#114)

the legacy travis-ci.org was using GH statuses API, while travis-ci.com switched to posting check-runs

Bump LS version used when resolving dependencies (#113)

rename oldmerge command to backport (#108)

fix typo in plugins watchdog task

only run plugin test notification on Mondays (#105)

Currently we print to Slack every 6 hours which plugins are broken.
This PR changes this to only print once on Monday. Monday was chosen since Travis usually triggers a test on all plugins every Friday.

Modify merge command to perform merge on target branch (#104)

The merge command has historically treated the list of branches as equals;
we would format-patch the change and then apply it to the list one by one.

This would mean that the github PR would not be marked as merged as we
were creating a new commit. This change modifies that, where the first
branch is merged with a normal git merge, and the remaining branches are
treated as before with 'git am'.

The new merge command will not append a "fixes #pr_number" sentence to
the commit message as it did before. Doing this would create a different
commit preventing the github PR from being marked as merged.

We keep the old command as "oldmerge".

This change also supports an empty branch list as an argument. In this
situation the PR's base branch will be used.

Resolves #54

[fix] missing versions.yml for plugin api gem (#103)

resolves #102

Feat: LOGSTASH_PATH auto expanding (#100)

* Feat: extract shell helpers + invent a handler

for mapping ENV keys to custom (processed) values

* Refactor: Fetch helper for effective file downloads

the library handles streaming file downloads for us
(we need this as we're going to fetch LS.tar.gz files)

* Fix: env (special char) parsing + use key symbol

* Refactor: Jarvis.execute args + logger default

* Feat: get LOGSTASH_PATH env expanding into place

* Feat: sensible LS env defaults for publish/run

* Fix: download - keep tmp file around for longer

* Test: fast test (stubbed) download/extraction

* Refactor: redo version qualifier e.g. [email protected]

* Change (to new) LOGSTASH_PATH defaults format

* Finally, only download on RELEASE/SNAPSHOT@ prefix

Merge pull request #94 from elastic/danhermann-patch-2

Update location_times.rb for current Logstash team