Remove pkt.Compact

[EthanHeilman]

As discussed in #105 Fixes JWS signing bug where we JSON unmarshalling breaks verification, the function pkt.Compact is intended to produce compact tokens that can pass signature verification. #105 makes pkt.Compact safe to use by just having it pull the corresponding saved token from the PK Token struct. This makes pkt.Compact redundant the developer could just pull the saved token themselves in fewer lines of code.

pkt.Compact, developers should simply use the compact token saved to the PK Token.
Rather than:

cicToken, err := pkt.Compact(pkt.Cic)

do this instead:

cicToken := pkt.CicToken

This issue should be resolved when we create a PR to remove pkt.Compact from the PK Token and from the examples. It depeneds on #105 being merged first.

[EthanHeilman]

pkt.Compact was removed in #110 closing this issue