[Fix] Usability improvements and new features

v0.2.0 release had bad binaries, so I'm cutting a new release to avoid confusion

[PR#3] Correct example in the readme
[PR#7] Update packer-provisioner-goss.go
Custom Gossfile suport (the --gossfile flag)
Tests now supports uploading directories - ignore support disabled (for now)
Username and Password for auth to download goss from custom authed locations
SSL cert check disable option - for internal services using self-signed certs
[PR#11] Make output format configurable