Fix ${line} in text format to mean line number

[apiology]

How to reproduce:

Create a reasonable-sounding .pronto.yml that looks like this, based on documentation from https://github.com/prontolabs/pronto#message-format:

 text:
   format: "%{path} %{line} %{runner} %{msg}"

Run against a project

Expected results:

Receive text output that looks like this:

Rakefile 124 rubocop Use `%i` or `%I` for an array of symbols.

Observed results:

Rakefile #<struct Pronto::Git::Line line=#<Rugged::Diff::Line:70253771778400 {line_origin: :addition, content: "task quality: [:pronto, :update_bundle_audit]\n">, patch=#<struct Pronto::Git::Patch patch=#<Rugged::Patch:70253763427640>, repo=#<Pronto::Git::Repository:0x007fca7539fe08 @repo=#<Rugged::Repository:70253763428080 {path: "/Users/broz/src/vincelifedaily/.git/"}>>>, hunk=#<Rugged::Diff::Hunk:70253771778940 {header: "@@ -115,7 +115,13 @@ end\n", count: 14}>> rubocop Use `%i` or `%I` for an array of symbols.

Notes:

Looks like the json_formatter.rb already looks for line number via the same method I'm proposing here. I'm guessing changing the meaning of message.line is a nonstarter given you'd have to change all of the runners at the same time, so using the decorator to adjust the meaning seemed like the right thing.

[doomspork]

@apiology this is wonderful, thank you! Would it be possible for you to update or add test coverage for this change?

[vinceatbluelabs]

@doomspork: Added - let me know what you think!

[doomspork]

Thank you @apiology! I'm going to give @mmozuras an opportunity to review this change before we merge.

I'm not sure whether or not you're participating in Digital Ocean's Hacktoberfest but I went ahead and tagged the PR for you anyways 😀

[apiology]

Thanks--wasn't aware of it, but just signed up!

[mmozuras]

@apiology thanks! 🙇

Exemplary pull request, love the fact that you've written a perfect "how to reproduce" 😄