Composer 2.0 compatibility

Composer 2.0 compatibility (#62)

* Update composer.json

* Support both Composer versions 1 and 2

* Replace deprecated constants

* Try to run on Travis with both Composer 1.x and 2.x versions

* Try to run on Travis with both Composer 1.x and 2.x versions

* Try to run on Travis with both Composer 1.x and 2.x versions

* Add askForUpdate for composer 2.0

2.5.0

Support Cobertura code coverage format

Compatibility with php-code-coverage 9

Merge pull request #59 from Codeception/php-code-coverage-9

Compatibility with php-code-coverage 9

Minor fixes

Minor but important fixes: #45 #46 #42 #47

Support for Codeception 2.4.0 and PHPUnit 7.0

Update c3.php

2.0.14

#35 Fixed Uncaught ArgumentCountError
#36 Added missing parameter to constructor of PHP_CodeCoverage_Report_PHPUnit aka SebastianBergmann\CodeCoverage\Report\Xml\Facade

PHPUnit CodeCoverage support

Export code coverage in PHPUnit format, see #33

Fixed Composer update

Fixed regression in 2.0.11 for composer update. See #30

Run installer only on update

Fix Composer notifications during install #29

Minor improvements

• crap4j support by @gimler #28
• speed up initialization by @gimler #27