Add tests to ensure environment variables are correctly forwarded (ba…

…marni#116)

Closes bamarni#63

Rewrite the tests (bamarni#77)

- Remove removed property from the PHPUnit config file
- Clarify the types in the tests
- Make the tests more explicit
  - Introduced helper assertions
  - Remove the assert from the test command
- Cleanup the generated directories after running the tests
- No longer generate a new directory for each test run
- Fix running the tests locally on OSX

Add forward mode (bamarni#67)

Fix deprecations from Symfony debug (bamarni#66)

Restore support for PHP 5.5.9+ (bamarni#55)

Add support for Composer2

Do not fail hard when installing no dev deps (bamarni#45)

remove 5.3 from travis config

release v1.1.0

update branch alias