cli: new arg: --output={json,text}
cli: new arg: --output={json,text}

Resolves #14

projectatomic/osbs-client,twaugh/osbs-client,bfontecc007/osbs-client,pombredanne/osbs-client,pbabinca/osbs,vrutkovs/osbs-client,TomasTomecek/osbs,jpopelka/osbs-client,vrutkovs/osbs-client,DBuildService/osbs-client,jpopelka/osbs-client,TomasTomecek/osbs,pbabinca/osbs,DBuildService/osbs-client,twaugh/osbs-client,bfontecc007/osbs-client,projectatomic/osbs-client,pombredanne/osbs-client