made the date format the same as in launches

waterskier2007 · waterskier2007 · commit ccb90c2f2cec · 2017-06-28T15:05:09.000-04:00
diff --git a/data/falcon9.rb b/data/falcon9.rb
@@ -5,7 +5,7 @@
   stages: 2,
   cost_per_launch: 62000000,
   success_rate_pct: 94,
-  first_flight: '06-04-2010',
+  first_flight: '2010-06-04',
   country: 'United States',
   company: 'SpaceX',
   height: {
