Fix error on Ruby 2.4.0.

TypeError: ActiveSupport::Duration can't be coerced into Integer

test/unit/lookups/esri_test.rb

@@ -25,7 +25,7 @@ class EsriTest < GeocoderTestCase
   end
 
   def test_query_for_geocode_with_token_and_for_storage
-    token = Geocoder::EsriToken.new('xxxxx', Time.now + 1.day)
+    token = Geocoder::EsriToken.new('xxxxx', Time.now + 60*60*24)
     Geocoder.configure(esri: {token: token, for_storage: true})
     query = Geocoder::Query.new("Bluffton, SC")
     lookup = Geocoder::Lookup.get(:esri)