Remove v0.1.2 tag so that latest tagged version is runnable

[sanjit-bhat]

I installed the latest v0.1.2 tag, spun up one server and one client, and tried registering a key. This gave me an inconsistent hash chain error.

I ran the client code through a debugger and realized that in the client's consistency checks for the register op, the client receives a very high epoch # from the server, whereas it has an epoch # of 0. This breaks the linked check.

I reverted back to v0.1.1 and had no immediate errors. My guess is that there were some intermediate changes that resulted in the system breaking, and while some fixes were proposed (e.g., #173), they weren't merged. If that's the case, it'd be great to remove the v0.1.2 tag so that go install github.com/coniks-sys/coniks-go/cli/coniksclient@latest works again, thanks!