Fix lint: add space before line continuation backslash

Author: MatheusRich

spec/data_customs/migration_spec.rb

@@ -188,8 +188,8 @@ def verify! = nil
       end
 
       expect { migration.run }.to output(
-        "🛃 Progress: ░░░░░░░░░░░░░░░░░░░░ 0%\n"\
-        "🛃 Progress: ████████████████████ 100%\n"\
+        "🛃 Progress: ░░░░░░░░░░░░░░░░░░░░ 0%\n" \
+        "🛃 Progress: ████████████████████ 100%\n" \
         "🛃 Data migration ran successfully!\n"
       ).to_stdout
     end