artist versions: fix uninitialized constant error.

Error appears intermittently depending on module load order.

Gemfile

@@ -45,6 +45,7 @@ gem 'retriable'
 gem 'redis'
 gem 'request_store'
 gem 'builder'
+gem 'did_you_mean'
 gem 'term-ansicolor', require: "term/ansicolor"
 
 # needed for looser jpeg header compat

Gemfile.lock

@@ -124,6 +124,7 @@ GEM
     delayed_job_active_record (4.1.3)
       activerecord (>= 3.0, < 5.3)
       delayed_job (>= 3.0, < 5)
+    did_you_mean (1.3.0)
     diff-lcs (1.3)
     docile (1.3.2)
     domain_name (0.5.20190701)
@@ -462,6 +463,7 @@ DEPENDENCIES
   dalli
   delayed_job
   delayed_job_active_record
+  did_you_mean
   diff-lcs
   dotenv-rails
   dtext_rb!

app/logical/set_diff.rb

@@ -27,7 +27,7 @@ class SetDiff
   end
 
   def find_similar(string, candidates, max_dissimilarity: 0.70)
-    distance = ->(other) { DidYouMean::Levenshtein.distance(string, other) }
+    distance = ->(other) { ::DidYouMean::Levenshtein.distance(string, other) }
     max_distance = string.size * max_dissimilarity
 
     candidates.select { |candidate| distance[candidate] <= max_distance }.sort_by(&distance).first