Improve perf on creating large file name

Author: cacheflow

spec/fcm_spec.rb

@@ -25,9 +25,7 @@
   end
 
   let(:large_file_name) do
-    1021.times.map do |el|
-      "a"
-    end.join('') + '.txt'
+    Array.new(1021) {|el| "a"}.join("") + ".txt"
   end
 
   let(:creds_error) do
@@ -69,7 +67,7 @@
     end
 
     it 'raises an error when passed a large path' do
-      expect do 
+      expect do
         FCM.new(large_file_name).__send__(:json_key)
       end.to raise_error(creds_error)
     end