Bump r10k from 3.5.1 to 3.7.0

Bumps [r10k](https://github.com/puppetlabs/r10k) from 3.5.1 to 3.7.0.
- [Release notes](https://github.com/puppetlabs/r10k/releases)
- [Changelog](https://github.com/puppetlabs/r10k/blob/master/CHANGELOG.mkd)
- [Commits](https://github.com/puppetlabs/r10k/compare/3.5.1...3.7.0)

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -14,7 +14,7 @@ end
 group :production do
   gem 'os',     '~> 1.1'
   gem 'puppet', puppetversion
-  gem 'r10k',   '~> 3.5'
+  gem 'r10k',   '~> 3.7'
   gem 'rugged', '~> 1.0'
   gem 'xmlrpc', '~> 0.3.0' if RUBY_VERSION >= '2.3'
 end

Gemfile.lock

@@ -39,7 +39,7 @@ GEM
       spdx-licenses (~> 1.0)
     minitar (0.9)
     mocha (1.11.2)
-    multi_json (1.14.1)
+    multi_json (1.15.0)
     multipart-post (2.1.1)
     necromancer (0.5.1)
     os (1.1.0)
@@ -112,7 +112,7 @@ GEM
       puppet-lint (~> 2.0)
       puppet-syntax (>= 2.0, < 4)
       rspec-puppet (~> 2.0)
-    r10k (3.5.1)
+    r10k (3.7.0)
       colored2 (= 3.1.2)
       cri (>= 2.15.10, < 3.0.0)
       fast_gettext (~> 1.1.0)
@@ -203,7 +203,7 @@ DEPENDENCIES
   puppet-lint-unquoted_string-check (~> 2.0)
   puppet-lint-variable_contains_upcase (~> 1.2)
   puppetlabs_spec_helper (~> 2.15)
-  r10k (~> 3.5)
+  r10k (~> 3.7)
   rspec-puppet (~> 2.6)
   rubocop (~> 0.87)
   rugged (~> 1.0)