Upgrade to plexus-archiver 2.7

Release Notes - Plexus Components - Version plexus-archiver-2.7

• • Bug
• [PLXCOMP-252] - Tar archivers cannot roundtrip own archives on windows, UTF8 bug

• • Improvement
• [PLXCOMP-253] - Switch default encoding to UTF-8

Release Notes - Plexus Components - Version plexus-archiver-2.6.4

• • Bug
• [PLXCOMP-45] - ignoreWebXML flag use is opposite of what the name implies.
• [PLXCOMP-107] - Fail to unzip archive, which contains file with name 'How_can_I_annotate_a_part_in_the_AAM%3F.Help' .
• [PLXCOMP-234] - plexus archiver TarOptions setDirMode and setMode do not do anything unless TarArchiver.setOptions is called

• • Improvement
• [PLXCOMP-250] - Upgrade maven-enforcer-plugin to 1.3.1