add kotlinx serializer

build.gradle.kts

@@ -1,18 +1,20 @@
 plugins {
     kotlin("jvm") version "1.6.0"
+    kotlin("plugin.serialization") version "1.6.0"
     `java-library`
     `maven-publish`
 }
 
 group = "org.bundleproject"
-version = "0.0.2"
+version = "0.0.3"
 
 repositories {
     mavenCentral()
 }
 
 dependencies {
     api(kotlin("stdlib-jdk8", "1.6.0"))
+    api("org.jetbrains.kotlinx:kotlinx-serialization-json:1.3.1")
 }
 
 tasks {

src/main/kotlin/org/bundleproject/libversion/Serializer.kt

@@ -0,0 +1,20 @@
+package org.bundleproject.libversion
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+
+class Serializer : KSerializer<Version> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("version", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): Version {
+        return Version.of(decoder.decodeString())
+    }
+
+    override fun serialize(encoder: Encoder, value: Version) {
+        encoder.encodeString(value.toString())
+    }
+}

src/main/kotlin/org/bundleproject/libversion/Version.kt

@@ -1,5 +1,8 @@
 package org.bundleproject.libversion
 
+import kotlinx.serialization.Serializable
+
+@Serializable(Serializer::class)
 class Version(
     val major: Int,
     val minor: Int = 0,