Fixed some tests.

app/Generator/Chart/PiggyBank/ChartJsPiggyBankChartGenerator.php

@@ -49,4 +49,4 @@ class ChartJsPiggyBankChartGenerator implements PiggyBankChartGenerator
 
         return $data;
     }
-}
+}

app/Generator/Chart/PiggyBank/GooglePiggyBankChartGenerator.php

@@ -38,4 +38,4 @@ class GooglePiggyBankChartGenerator implements PiggyBankChartGenerator
 
         return $chart->getData();
     }
-}
+}

app/Generator/Chart/PiggyBank/PiggyBankChartGenerator.php

@@ -17,4 +17,4 @@ interface PiggyBankChartGenerator
      * @return array
      */
     public function history(Collection $set);
-}
+}