chore: Update build toolchain (#23)

This pull requests updates the project as follows:
1. **Update Gradle version to 4.8**
   This allows us to make use of new features such as native JUnit 5 integration and the build cache.
2. **Update Gradle build configuration according to new changes**
   This change allows us to share configuration across modules and easily change the versions for shared dependencies. In addition, we now make use of the `java-library` plugin which allows for various optimizations. See https://docs.gradle.org/current/userguide/java_library_plugin.html
3. **Add support for Jacoco**
    We add support code coverage tracking via the latest version of Jacoco which has increasing support for Kotlin.

Closes #22 

3 files changed, 90 insertions, 6 deletions

diff --git a/gradle/kotlin.gradle b/gradle/kotlin.gradle
new file mode 100644
index 00000000..04f67ae8
--- /dev/null
+++ b/gradle/kotlin.gradle
@@ -0,0 +1,85 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/* Default configuration for Kotlin projects */
+apply plugin: 'kotlin'
+apply plugin: 'org.jetbrains.dokka'
+apply plugin: 'jacoco'
+
+sourceCompatibility = 1.8
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
+kotlin {
+    experimental {
+        coroutines "enable"
+    }
+}
+
+/* Configure test setup */
+test {
+    useJUnitPlatform {}
+
+    testLogging {
+        events 'passed', 'skipped', 'failed'
+    }
+
+    reports {
+        html.enabled = true
+    }
+
+    finalizedBy jacocoTestReport
+}
+
+/* Coverage */
+repositories {
+    // This repository is needed to get the latest snapshot of Jacoco
+    maven { url = "https://oss.sonatype.org/content/repositories/snapshots" }
+}
+
+jacoco {
+    // We use the latest snapshot of Jacoco in order to get it to ignore Kotlin-generated code
+    toolVersion = jacoco_version
+}
+
+jacocoTestReport {
+    reports {
+        html.enabled = true
+        xml.enabled = true
+    }
+}
+
+/* Documentation generation */
+dokka {}
+
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 24dcc970..1948b907 100644
--- a/gradle/wrapper/gradle-wrapper.jar
+++ b/gradle/wrapper/gradle-wrapper.jar
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 5c2e2870..d2c45a4b 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Tue Aug 29 14:12:50 CEST 2017

-distributionBase=GRADLE_USER_HOME

-distributionPath=wrapper/dists

-zipStoreBase=GRADLE_USER_HOME

-zipStorePath=wrapper/dists

-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-rc-2-all.zip

+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.8-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists