remove script that triggered now removed retest tests
include project app dirs in release lib_dirs to search
include providers listed in plugins env
Merge pull request #75 from talentdeficit/remove_config_script

remove script that triggered now removed retest tests
Merge pull request #76 from tsloughter/master

Small release fix and new plugin loading
update plugin install code
Merge pull request #77 from tsloughter/master

update plugin install code
remove no longer relevant test machinery in rebar_erlc_compiler