BAEL-2910 MockMvc Kotlin DSL

* configured spring repo in the 'parent-kotlin' model
  to allow using spring's milestone artifacts
* configured jackson kotlin module in the 'parent-kotlin'
  to allow easy use of kotlin data classes with jackson
* switched spring-mvc-kotlin from explicit spring
  dependencies to spring-boot
* mockmvc dsl article's source and tests

spring-mvc-kotlin/src/test/kotlin/com/baeldung/kotlin/mockmvc/MockMvcControllerTest.kt

@@ -0,0 +1,61 @@
+package com.baeldung.kotlin.mockmvc
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity.status
+import org.springframework.test.context.junit4.SpringRunner
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.post
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders
+import org.springframework.test.web.servlet.result.MockMvcResultHandlers
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers
+
+@RunWith(SpringRunner::class)
+@WebMvcTest
+class MockMvcControllerTest {
+
+    @Autowired lateinit var mockMvc: MockMvc
+    @Autowired lateinit var mapper: ObjectMapper
+
+    @Test
+    fun `when supported user is given then raw MockMvc-based validation is successful`() {
+        mockMvc.perform(MockMvcRequestBuilders
+                                .post("/mockmvc/validate")
+                                .accept(MediaType.APPLICATION_JSON)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .content(mapper.writeValueAsString(Request(Name("admin", "")))))
+                .andExpect(MockMvcResultMatchers.status().isOk)
+                .andExpect(MockMvcResultMatchers.content().contentType(MediaType.APPLICATION_JSON))
+                .andExpect(MockMvcResultMatchers.content().string("{}"))
+    }
+
+    @Test
+    fun `when supported user is given then kotlin DSL-based validation is successful`() {
+        doTest(Request(Name("admin", "")), Response(null))
+    }
+
+    @Test
+    fun `when unsupported user is given then validation is failed`() {
+        doTest(Request(Name("some-name", "some-surname")), Response(MockMvcController.ERROR))
+    }
+
+    private fun doTest(input: Request, expectation: Response) {
+        mockMvc.post("/mockmvc/validate") {
+            contentType = MediaType.APPLICATION_JSON
+            content = mapper.writeValueAsString(input)
+            accept = MediaType.APPLICATION_JSON
+        }.andExpect {
+            status { isOk }
+            content { contentType(MediaType.APPLICATION_JSON) }
+            content { json(mapper.writeValueAsString(expectation)) }
+        }
+    }
+}
+
+@SpringBootApplication
+class MockMvcApplication