Using upstream goconst

[iwankgb]

Thanks to jgautheron/goconst#11 we should be able to get rid of goconst fork. Closes #1495.

[iwankgb]

jgautheron/goconst#13 must be merged and new version released before we proceed.

[iwankgb]

@golangci/team, it seems that problem is more complicated here. Some time ago (our fork was based on 3-year old commit) new feature was introduced to goconst. It cause goconst to notice repeated strings in function calls. With current settings in .golangcilint.yml there are 50 places that would have to be fixed. When min-length and min-occurrences are set to 3 (default values) there is only 11 of them.

Taking above into consideration we have 2 options, I think:

1. Fix violations and publish clear warning to the users stating that update in goconst may force them to do additional work.
2. Reach out to @jgautheron and try to make checks configurable, with same default config in our project.

Second option sounds much more reasonable to me and I would file all the necessary PRs.

Third option (that I consider a non-option) would be to keep maintaining our fork and deviate from the upstream. This is probably the worst possible idea. In case of no feedback I will proceed with option 2 (if @jgautheron is open to such a solution).

[ernado]

Can we use default excludes to mitigate (1) or error messages are same in both cases?

[iwankgb]

@ernado it should be possible, I will investigate.

[iwankgb]

@ernado message is the same for all types of violation and I can't really tell one from another.

[iwankgb]

I have file a PR against upstream goconst repository. If it's merged we should be able to start using upstream seamlessly.

[iwankgb]

@ernado, a quick look would be appreciated :)

[ernado]

LGTM, thank you!