upgrade with specific version number fails; says package already installed

[cweiske]

Pyrus should try to upgrade instead of telling me that the package is already installed:

$ pyrus info pear/php_codesniffer |grep Version
Version:      1.5.0RC2 (API 1.5.0RC2), Stability:    beta (API beta)

$ pyrus upgrade pear/php_codesniffer-1.5.0RC3
Pyrus version 2.0.0a4 SHA-1: 72271D92C3AA1FA96DF9606CD538868544609A52
Using PEAR installation found at /opt/phpfarm/inst/php-5.3.27/pear
Skipping installed package pear.php.net/PHP_CodeSniffer