Bump Gradle, Kotlin, and toml4j versions.

Apparently, Gradle was incompatible with Java 10, and neither was
toml4j.

build.gradle

@@ -1,6 +1,6 @@
 buildscript {
-    ext.kotlin_version = '1.1.3'
-    ext.dokka_version = '0.9.15'
+    ext.kotlin_version = '1.2.40'
+    ext.dokka_version = '0.9.16'
 
     repositories {
         jcenter()
@@ -23,7 +23,7 @@ subprojects {
     }
 
     dependencies {
-        compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:1.1.3"
+        compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:1.2.40"
     }
 }
 

fx/build.gradle

@@ -1,7 +1,7 @@
 apply plugin: 'application'
 
 dependencies {
-    compile 'com.moandjiezana.toml:toml4j:0.7.1'
+    compile 'com.moandjiezana.toml:toml4j:0.7.2'
     compile project(':core')
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Fri Jul 28 17:18:51 PDT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-bin.zip