Upgraded gradle to 6.6.1.

Upgraded kotlin to 1.4.10.
Upgraded assertj to 3.17.2.
Upgraded junit-jupiter to 5.7.0.
Other minor upgrades.

build.gradle

@@ -1,13 +1,13 @@
 plugins {
     id 'java'
-    id 'org.jetbrains.intellij' version '0.4.21'
+    id 'org.jetbrains.intellij' version '0.4.26'
-    id 'org.jetbrains.kotlin.jvm' version '1.4.0-rc'
+    id 'org.jetbrains.kotlin.jvm' version '1.4.10'
     id 'jacoco'
-    id 'com.github.kt3k.coveralls' version '2.10.1'
+    id 'com.github.kt3k.coveralls' version '2.10.2'
 }
 
 group 'de.platon42'
-version '1.10'
+version '1.11'
 
 repositories {
     mavenCentral()
@@ -20,22 +20,28 @@ repositories {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
-    testImplementation "org.assertj:assertj-core:3.16.1"
+    testImplementation "org.assertj:assertj-core:3.17.2"
     testImplementation "org.assertj:assertj-guava:3.4.0"
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.2'
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.0'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.6.2'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
     testImplementation "org.jetbrains.kotlin:kotlin-test"
 //    testImplementation "org.jetbrains.kotlin:kotlin-test-junit"
 }
 
 compileKotlin {
     kotlinOptions.jvmTarget = "1.8"
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
 }
+
 compileTestKotlin {
     kotlinOptions.jvmTarget = "1.8"
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
 }
+
 intellij {
-    version '2020.2'
+    version '2020.2.2' // LATEST-EAP-SNAPSHOT
 //    pluginName 'Concise AssertJ Optimizing Nitpicker (Cajon)'
     updateSinceUntilBuild false
     plugins = ['java']
@@ -43,10 +49,12 @@ intellij {
 
 patchPluginXml {
     changeNotes """
-  <h4>V1.10 (31-Jul-20) Friday the 31st Edition</h4>
+  <h4>V1.11 (03-Oct-20) Day of German Unity Edition</h4>
     <ul>
-      <li>Updated libraries to the latest versions (including AssertJ 3.16.1 and Kotlin 1.40-rc).
+      <li>Now is being built with JDK 11 (with Java 8 target).
-      <li>Fixed two possible index out of bounds exceptions in ExtractorReferenceContributor and BogusAssertionInspection.
+      <li>Updated various dependencies and AssertJ 3.17.2.
+      <li>Fixed the ImplicitAssertionInspection that broke the plugin with IntelliJ 2020.3 EAP as reported by Frédéric Thomas. Thanks!
+      <li>Added new singleElement() from AssertJ >= 3.17.0 to ImplicitAssertionInspection.
     </ul>
   <p>Full changelog available at <a href="https://github.com/chrisly42/cajon-plugin#changelog">Github project site</a>.</p>
 """
@@ -60,7 +68,7 @@ test {
 }
 
 jacoco {
-    toolVersion = '0.8.5'
+    toolVersion = '0.8.6'
 }
 
 jacocoTestReport {

gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-all.zip