Get Travis tests working again on HHVM

[johnbillion]

Another part of the push to get all of our Travis builds working again.

The Travis jobs that run on HHVM have been erroring for a while now. This aims to fix that by:

• Using PHPUnit 5.7 / 4.8 / 3.6 depending on the PHP version (5.7 for HHVM).
• Correcting the path to Composer's global bin dir, which for some reason differs on the boxes that run HHVM.
• Not breaking everything else at the same time.

Note that the HHVM tests still fail, but that's a separate issue.

Related: #40086, #39822, #35105

[johnbillion]

In 40269:

Build/Test tools: Get Travis builds working on HHVM again.

This change moves to specifying the PHPUnit version for all PHP versions, and fixes an issue where the Composer global bin directory is not at ~/.composer/vendor/bin on the boxes that are used for HHVM builds.

See #40100

[johnbillion]

In 40271:

Build/Test tools: Don't install PHPUnit on the travis:js builds. Saves a couple of minutes of build time.

See #40100

[johnbillion]

In 40272:

Build/Test tools: Get Travis builds working on HHVM again.

This change moves to specifying the PHPUnit version for all PHP versions, and fixes an issue where the Composer global bin directory is not at ~/.composer/vendor/bin on the boxes that are used for HHVM builds.

See #40100

Merges [40269] and [40271] to the 4.7 branch.

[johnbillion]

In 40273:

Build/Test tools: Don't install PHPUnit on the travis:js builds. Saves a couple of minutes of build time.

See #40100

Merges [40269] and [40271] to the 4.6 branch.

[johnbillion]

In 40274:

Build/Test tools: Get Travis builds working on HHVM again.

This change moves to specifying the PHPUnit version for all PHP versions, and fixes an issue where the Composer global bin directory is not at ~/.composer/vendor/bin on the boxes that are used for HHVM builds.

See #40100

Merges [40269] and [40271] to the 4.5 branch.

[johnbillion]

In 40276:

Build/Test tools: Update .travis.yml to include latest improvements from trunk.

• Explicitly use PHPUnit 5.7 for the PHP 7 builds on Travis.
• On Travis CI install and use the node version which is specified in package.json.
• Add some more debugging to Travis and bring the format of the Xdebug fix inline with branches.
• Get Travis builds working on HHVM again.

Merges [40255], [40257], [40258], [40259], [40269], and [40271] to the 4.4 branch.

See #35105, #40100

[johnbillion]

In 40277:

Build/Test tools: Update .travis.yml to include latest improvements from trunk.

• Explicitly use PHPUnit 5.7 for the PHP 7 builds on Travis.
• On Travis CI install and use the node version which is specified in package.json.
• Add some more debugging to Travis and bring the format of the Xdebug fix inline with branches.
• Get Travis builds working on HHVM again.
• In addition, brings the Slack notification settings up to date.

Merges [40255], [40257], [40258], [40259], [40269], and [40271] to the 4.3 branch.

See #35105, #40100, #30755

[ocean90]

In 40282:

Build/Test Tools: Update .travis.yml to include latest improvements from trunk.

• Explicitly use PHPUnit 5.7 for the PHP 7 builds on Travis.
• On Travis CI install and use the node version which is specified in package.json.
• Add some more debugging to Travis and bring the format of the Xdebug fix inline with branches.
• Get Travis builds working on HHVM again.
• In addition, brings the Slack notification settings up to date and allows Travis CI to cache the node_modules directory.

Merge of [40255], [40257-40259], [40269], and [40271] to the 4.2 branch.

See #35105, #40100, #30755, #36291, #36490.

[ocean90]

In 40286:

Build/Test Tools: Update .travis.yml to include latest improvements from trunk.

• On Travis CI install and use node version 0.10.48 to ensure correct node-sass builds.
• Explicitly use PHPUnit 5.7 for the PHP 7 builds on Travis.
• Add some more debugging to Travis and bring the format of the Xdebug fix inline with branches.
• Get Travis builds working on HHVM again.
• In addition, brings the Slack notification settings up to date and allows Travis CI to cache the node_modules directory.

Merge of [40255], [40257],[40259], [40269], and [40271] to the 4.1 branch.

See #35105, #40100, #30755, #36291, #36490.

[ocean90]

In 40288:

Build/Test Tools: Update .travis.yml to include latest improvements from trunk.

• On Travis CI install and use node version 0.10.48 to ensure correct node-sass builds.
• Explicitly use PHPUnit 5.7 for the PHP 7 builds on Travis.
• Add some more debugging to Travis and bring the format of the Xdebug fix inline with branches.
• Get Travis builds working on HHVM again.
• In addition, brings the Slack notification settings up to date and allows Travis CI to cache the node_modules directory.

Merge of [40255], [40257],[40259], [40269], and [40271] to the 4.0 branch.

See #35105, #40100, #30755, #36291, #36490.

[johnbillion]

Superseded by #40548.