Convert Gradle scripts to Kotlin (#15)

build.gradle.kts

@@ -0,0 +1,35 @@
+import java.io.BufferedReader
+import java.io.InputStreamReader
+
+plugins {
+    `java-library`
+}
+
+val junitVersion = "4.13.2"
+
+repositories {
+    mavenCentral()
+}
+
+group = "uk.co.mainwave.mimetypes"
+version = getVersionFromGit()
+
+java.sourceCompatibility = JavaVersion.VERSION_1_8
+
+dependencies {
+    testImplementation("junit:junit:$junitVersion")
+}
+
+fun getVersionFromGit(): String {
+    val processBuilder = ProcessBuilder(listOf("git", "describe", "--tags", "--always"))
+    try {
+        val process = processBuilder.start()
+        val reader = BufferedReader(InputStreamReader(process.inputStream))
+        val output = StringBuilder()
+        output.append(reader.readLine())
+        process.waitFor()
+        return output.toString()
+    } catch (e: Exception) {
+        return "1.0.0"
+    }
+}

settings.gradle.kts

@@ -0,0 +1,2 @@
+rootProject.name = "mimetypes"
+