Remove deprecated grpc methods

[abjeni]

Removing deprecated grpc methods and using the new NewClient method instead of DialContext.
This also removes the gorums.WithDialTimeout method.
This means that you cannot know if the grpc server is not responding before you use any rpc call.

• list of removed methods

1. grpc.DialContext
2. grpc.WithBlock
3. grpc.grpc.WithReturnConnectionError

• References
  grpc anti-patterns

Fixes #196

[meling]

Great job!

[meling]

For the record, I would like to get this one into master before the multiparty PR.

@abjeni Could you check how bad the conflicts would be if we merge this one into master before merging the Multiparty PR?

I'm sure there is a smart way to do it, but one naive way would be to do another clone of the repo to a tmp folder, and checkout this branch, and then run:

git switch Salhus/issue196/remove-deprecated-methods
git merge multiparty

Alternatively, the other way around.

(If you are confident with git, you can do it on your local working copy and roll back.)

[abjeni]

I used the naive method and only got one merge conflict where we both modified the managerOptions struct in file opts.go. I also did not notice any deprecated grpc methods.

[meling]

Excellent, one merge conflict is not a problem...