Merge branch 'release-0.2.1'

* Fixed issue #7 - Remove "unload_plugins"
* Fixed 'import' in 'pyraxshell::load_plugins()'
* Fixed issue #6
* Fixed issue #10
v0.2.2
Merge branch 'release-0.2.2'
v0.2.2
Merge branch 'master' into release-0.2.2
Merge branch 'release-0.2.2' into develop