Fix for encoding Decimal (#4)

Also make options optional when turning into data

Author: nighthawk

Sources/GeoJSONKit/GeoJSON+Codable.swift

@@ -78,6 +78,14 @@ extension GeoJSON.GeometryObject: Codable {
         try container.encode(triple, forKey: .coordinates)
       } else if let quatruple = coordinates as? [[[[Double]]]] {
         try container.encode(quatruple, forKey: .coordinates)
+      } else if let single = coordinates as? [Decimal] {
+        try container.encode(single, forKey: .coordinates)
+      } else if let double = coordinates as? [[Decimal]] {
+        try container.encode(double, forKey: .coordinates)
+      } else if let triple = coordinates as? [[[Decimal]]] {
+        try container.encode(triple, forKey: .coordinates)
+      } else if let quatruple = coordinates as? [[[[Decimal]]]] {
+        try container.encode(quatruple, forKey: .coordinates)
       } else {
         throw CodingError.unsupportedCoordinateCount
       }

Sources/GeoJSONKit/GeoJSON.swift

@@ -465,7 +465,7 @@ public struct GeoJSON: Hashable {
   }
 
 
-  public func toData(options: JSONSerialization.WritingOptions) throws -> Data {
+  public func toData(options: JSONSerialization.WritingOptions = []) throws -> Data {
     return try JSONSerialization.data(withJSONObject: toJSON(), options: options)
   }