add describe_tags api support
add instance spec utility function, support app env, .config anf .json
partually ransomr commit b8a4aced842499a12cd41a752de6a8b5260fe661
drop instnace_spec support
fix: create_tags with default config
merger with upsteram
fix: add create_tags with default_config
fix: remove sasl from erlcloud (client app desides on loggin fw)
Merge pull request #27 from fogfish/master

minor fixes on api