warning/errors to stderr

[glensc]

hi

please change so that warnings and errors are printed to stderr, not stdout.

for example my deploy script contains this snippet:

    $ composer licenses --no-dev --no-ansi > deps

now the warning that composer is too old, should not be stored in that file, but rather in stderr:

$ cat deps
Warning: This development build of composer is over 30 days old. It is recommended to update it by running "/home/glen/Dropbox/
bin/composer.phar self-update" to get the latest version.
...
Licenses: GPL-2.0
Dependencies:

  components/jquery                    1.8.3                MIT     
  components/jquery-blockui            2.70                 MIT, GPL
  components/jquery-chosen             1.2.0                MIT

[Seldaek]

This has been fixed, but possibly in the last 30days, so I guess you don't see it in your >30days version :)