Checking in changes prior to tagging of version 1.17.1.
Fix undefined property
further fix for jsonc extension install
Checking in changes prior to tagging of version 1.17.2.
Merge branch 'develop'

Conflicts:
	composer.json
Checking in changes prior to tagging of version 1.18.0.
Fixes the description to enable version info prompt.
Merge pull request #419 from shinnya/fix/version_info_on_prompt

Fixes the description to enable version info prompt.
Add test cases to ConfigTest.

Fixes the test cases using Config::getCurrentPhpDir().

Fixed PATH and PATH_WITHOUT_PHPBREW was broken in ZSH. fixes #420

Signed-off-by: Rack Lin <racklin@gmail.com>

fix "PHP Warning:  stream_get_contents():" when proc_open not set into variable

fix return value to test when calling Utils::system method

Uses environment variables defined in phpunit.xml in ConfigTest.

Adds test cases for methods in PhpBrew\Config that have side effects.

Returns environment variables back to the original value after each test case in CommandTestCase.

Unset PHPBREW_HOME and PHPBREW_ROOT before running phpunit.