Tidied up Luhn checksum op

tests/operations/tests/LuhnChecksum.mjs

@@ -11,7 +11,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data",
         input: "35641709012469",
-        expectedOutput: "Checksum: 7\n\nCheckdigit: 0\n\nLuhn Validated String: 356417090124690",
+        expectedOutput: "Checksum: 7\nCheckdigit: 0\nLuhn Validated String: 356417090124690",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -22,7 +22,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data 2",
         input: "896101950123440000",
-        expectedOutput: "Checksum: 5\n\nCheckdigit: 1\n\nLuhn Validated String: 8961019501234400001",
+        expectedOutput: "Checksum: 5\nCheckdigit: 1\nLuhn Validated String: 8961019501234400001",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -33,7 +33,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data 3",
         input: "35726908971331",
-        expectedOutput: "Checksum: 6\n\nCheckdigit: 7\n\nLuhn Validated String: 357269089713317",
+        expectedOutput: "Checksum: 6\nCheckdigit: 7\nLuhn Validated String: 357269089713317",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -55,7 +55,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on empty data",
         input: "",
-        expectedOutput: "0",
+        expectedOutput: "",
         recipeConfig: [
             {
                 op: "Luhn Checksum",