Pre-release tags with hyphens are truncated

[jschnare]

SemVer 2 says a "pre-release version MAY be denoted by appending a hyphen and a series of dot separated identifiers" and identifiers "comprise only ASCII alphanumerics and hyphen [0-9A-Za-z-]".

if the version is '0.0.1-foo-bar.baz', the pre-release should be ['foo-bar', 'baz']. Instead, it returns 'foo' - explode('-', $version) evaluates to ['0.0.1', 'foo', 'bar.baz'], and only the first two elements are assigned.

This change will return ['0.0.1', 'foo-bar.baz'], which can then be exploded on '.'

[Octen]

Your pull request break existing unit tests.

I added a pull request with the addition of unit testing, and modification with the help of your code.

[Octen]

Warning, your limit parameter is incorrect :

<?php
print_r(preg_split('/-/', '1.2.3-pre-release', 1));
?>

The above example will output, and break the unit testing :

Array
(
    [0] => 1.2.3-pre-release
)

But, fix limit to 2 :

<?php
print_r(preg_split('/-/', '1.2.3-pre-release', 2));
?>

The above example will output:

Array
(
    [0] => 1.2.3
    [1] => pre-release
)

Expected return for the need of your pull request