Fix URI.encode deprecation warnings for Ruby 3 compatibility

[tjvman]

Unit tests passed against Ruby 2.7.2 and Ruby 3.0.3.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/180829543

The labels on this github issue will be updated when the story is started.

[sethboyles]

This addresses #68

[bgandon]

I've pushed some more adjustments in order to remove warnings when running unit tests.
Tested successfully with Ruby 3.1.0, 2.7.2 and 3.0.2.

@strehle, could you please review and merge this PR?

[tjvman]

@bgandon @strehle If/when this PR is merged, do y'all plan to cut a release of the gem?

We're planning to upgrade to Ruby 3, and we want to have a plan for how we consume this gem - through RubyGems release, targeting master (not sure how stable master is meant to be), or some other method.

[strehle]

I can merge - no matter, but I cannot release to rubygems, so @peterhaochen47 @bruce-ricard either you have the key to do a release or do you know where in pipeline there is a ship-it ?
I see only cf-uaac (command line tool itself) pipeline , e.g. https://hush-house.pivotal.io/teams/cf-uaa/pipelines/cf-uaac

I will join next WG status meeting on thursday, but we need some colleague(s) from vmware

[bgandon]

@tjvman I think Markus has covered the organisational challenge around publishing a new version of this Gem. This is certainly still in the hands of VMware even though other members of the CFF Working Group like SAP (which I'm part of) should also have the ability to cut new releases.

Anyway, cutting a new version of this Gem is a major step in order to get proper Ruby 3 support into cf-uaac, which will be a great achievement! 😃

And we are very close to it, as I've pushed the tested code in cloudfoundry/cf-uaac#95.

[strehle]

see comment, rest ok

[strehle]

@bgandon can you please resolve conflicts and rebase maybe you use githubActions .
We can discuss #78 in next WG meeting