fix zsh comptability issue, #404
Fixed php prefix issue #405
Merge pull request #406 from mdkholy/php-prefix-issue-fix

Fixed php prefix issue
add a makefile
add ext test script to Makefile
fix Makefile clean task
add test/extension to Makefile, equivalent to phpunit --group extension
remove test already covered on ReleaseListTest
fix ReleaseListTest so it won't fail everytime php-releases.json is renewed
annotate all tests with `@small`, `@large`, `@group extension`, `@group command`

- test quick things: phpunit --group small
- test slow operations: phpunit --group large
- test just commands (slow): phpunit --group command
- test just extensions: phpunit --group extension
fix PHPBREW_ROOT and PHPBREW_HOME paths on CommandTestCase
make test suite silent by default
remove die calls from ExtractTask, no more dies please
remove unnecessary ob_start and ob_end_clean call from InstallCommandTest.php
fix InstallCommandTest
EOF with new line [skip ci]
run init before DownloadCommandTest

test suites should be self contained  or have an explicit
`@depends AnotherOtherTestCase` annotation, in this case the DownloadCommanTest
depended on init command to be run before the test suite.
swap ob_clean() call with a propper ob_end_clean() call
this aims to solve risk tests with message "tested code did not (only) close its own output buffers"
skipping bad ExtensionCommandTest, it looks like they never passed before

ExtensionCommandTest was not being executed before die calls were removed and
it looks like they never passed before because "phpbrew ext <commands>" are
being run agains system php, therefore they can't pass
avoid github extension fethcing error while asset is not on master
this extension list is still a controversial feature anyway #401, #402