CF CredHub KeyStore

[kinjelom]

Implementation of CredHub Keystore for MinIO's KES with Mutual TLS Authentication.

[harshavardhana]

@kinjelom please run these tests locally and update the PR once you have done those changes

@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/863814ab34054f4912c0b9dfab85979ec83662f2)
[863814a](https://github.com/minio/kes/pull/482/commits/863814ab34054f4912c0b9dfab85979ec83662f2)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/b2886adafb917339ba4ae7c6fa6bd849f1a79748)
[b2886ad](https://github.com/minio/kes/pull/482/commits/b2886adafb917339ba4ae7c6fa6bd849f1a79748)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/db0956d90dc0d4752ca47308c6a3bf2f26ac3986)
[db0956d](https://github.com/minio/kes/pull/482/commits/db0956d90dc0d4752ca47308c6a3bf2f26ac3986)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/aba8964c5ecababb199c4ba65834f49d5ff42405)
[aba8964](https://github.com/minio/kes/pull/482/commits/aba8964c5ecababb199c4ba65834f49d5ff42405)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/1e20962698a84d2d3ab855b98edec5c48f3d3fa9)
[1e20962](https://github.com/minio/kes/pull/482/commits/1e20962698a84d2d3ab855b98edec5c48f3d3fa9)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/65224a6f66c5083f9590b2371628005e53616366)
[65224a6](https://github.com/minio/kes/pull/482/commits/65224a6f66c5083f9590b2371628005e53616366)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/4ab70db1fbb5222972f09750f0fcec3992275243)
[4ab70db](https://github.com/minio/kes/pull/482/commits/4ab70db1fbb5222972f09750f0fcec3992275243)
@kinjelom
[Lint related changes](https://github.com/minio/kes/pull/482/commits/1932d1542a14f7c1de4c66b4f068500fef9c8e66)
[1932d15](https://github.com/minio/kes/pull/482/commits/1932d1542a14f7c1de4c66b4f068500fef9c8e66)

Don't use our CI to test fixing linter issues.

[harshavardhana]

Please submit when all the linter changes are finished. Please stop abusing our CI.

[kinjelom]

@harshavardhana sorry, I hope this is enough:

golangci-lint run  --config ./.golangci.yml -v
INFO [config_reader] Used config file .golangci.yml 
INFO [lintersdb] Active 13 linters: [durationcheck gocritic gofumpt goimports gomodguard govet ineffassign misspell revive staticcheck tenv unconvert unused] 
INFO [loader] Go packages loading at mode 575 (deps|compiled_files|files|imports|name|types_sizes|exports_file) took 366.196935ms 
INFO [runner/filename_unadjuster] Pre-built 0 adjustments in 6.371575ms 
INFO [linters_context/goanalysis] analyzers took 0s with no stages 
INFO [runner] Issues before processing: 37, after processing: 0 
INFO [runner] Processors filtering stat (out/in): skip_dirs: 37/37, autogenerated_exclude: 32/37, cgo: 37/37, filename_unadjuster: 37/37, path_prettifier: 37/37, skip_files: 37/37, exclude: 0/32, identifier_marker: 32/32 
INFO [runner] processing took 1.057095ms with stages: identifier_marker: 362.826µs, autogenerated_exclude: 298.808µs, path_prettifier: 257.183µs, skip_dirs: 114.799µs, exclude: 14.29µs, cgo: 4.629µs, filename_unadjuster: 1.335µs, nolint: 504ns, max_same_issues: 452ns, fixer: 348ns, severity-rules: 330ns, skip_files: 290ns, exclude-rules: 252ns, sort_results: 244ns, diff: 175ns, uniq_by_line: 175ns, max_from_linter: 154ns, source_code: 86ns, path_shortener: 81ns, max_per_file_from_linter: 72ns, path_prefixer: 62ns 
INFO [runner] linters took 314.863551ms with stages: goanalysis_metalinter: 313.762579ms 
INFO File cache stats: 0 entries of total size 0B 
INFO Memory: 8 samples, avg is 48.5MB, max is 103.4MB 
INFO Execution took 690.863751ms