Kotlin jvm field (#2610)

* Add project for hibernate immutable article
Add Event entity
Add hibernate configuration file
Add hibernateutil for configuration
Add test to match snippets from article

* Update master

* Jvm Field
Add sample classes
Include test for sample classes

kotlin/src/main/kotlin/com/baeldung/kotlin/JvmSample.kt

@@ -0,0 +1,12 @@
+package com.baeldung.kotlin
+
+class JvmSample(text:String) {
+    @JvmField
+    val sampleText:String = text
+}
+
+class CompanionSample {
+    companion object {
+        @JvmField val MAX_LIMIT = 20
+    }
+}

kotlin/src/test/kotlin/com/baeldung/kotlin/JvmSampleTest.kt

@@ -0,0 +1,26 @@
+package com.baeldung.kotlin
+
+import org.junit.Before
+import org.junit.Test
+import kotlin.test.assertTrue
+
+class JvmSampleTest {
+
+    var sample = ""
+
+    @Before
+    fun setUp() {
+        sample = JvmSample("Hello!").sampleText
+    }
+
+    @Test
+    fun givenField_whenCheckValue_thenMatchesValue() {
+        assertTrue(sample == "Hello!")
+    }
+
+    @Test
+    fun givenStaticVariable_whenCheckValue_thenMatchesValue() {
+        // Sample when is treated as a static variable
+        assertTrue(CompanionSample.MAX_LIMIT == 20)
+    }
+}