Adding symmetrical serialization specification for UInt32

src/main/scala/org/bitcoins/core/number/NumberType.scala

@@ -226,7 +226,7 @@ object UInt32 extends Factory[UInt32] with BitcoinSLogger with BaseNumbers[UInt3
     UInt32Impl(individualByteValues.sum.toLong, BitcoinSUtil.encodeHex(bytes))
   }
 
-  def apply(long : Long) : UInt32 = UInt32Impl(long, BitcoinSUtil.encodeHex(BigInt(long).toByteArray))
+  def apply(long : Long) : UInt32 = UInt32Impl(long, BitcoinSUtil.encodeHex(long))
 
 }
 

src/main/scala/org/bitcoins/core/util/BitcoinSUtil.scala

@@ -28,6 +28,16 @@ trait BitcoinSUtil extends NumberUtil {
 
   def encodeHex(byte : Byte) : String = encodeHex(Seq(byte))
 
+  /**
+    * Encodes a long number to a hex string, pads it with an extra '0' char
+    * if the hex string is an odd amount of characters
+    * @param long
+    * @return
+    */
+  def encodeHex(long : Long) : String = long.toHexString.length % 2 match {
+    case 1 => "0" + long.toHexString
+    case _ : Int => long.toHexString
+  }
   /**
    * Tests if a given string is a hexadecimal string
    * @param str

src/test/scala/org/bitcoins/core/number/UInt32Specification.scala

@@ -95,4 +95,11 @@ class UInt32Specification extends Properties("UInt32") with BitcoinSLogger {
     }
   }
 
+  property("serialization symmetry") = {
+    Prop.forAll(NumberGenerator.uInt32s) { uInt32 : UInt32 =>
+      UInt32(uInt32.hex) == uInt32
+      UInt32(uInt32.hex).hex == uInt32.hex
+    }
+  }
+
 }