Include wdm.avoidShutdownHook config key (issue #839)

Author: bonigarcia

src/main/java/io/github/bonigarcia/wdm/WebDriverManager.java

@@ -1803,7 +1803,7 @@ protected Capabilities getMergedCapabilities() {
     }
 
     protected void addShutdownHookIfRequired() {
-        if (!shutdownHook) {
+        if (!shutdownHook && !config().isAvoidShutdownHook()) {
             Runtime.getRuntime()
                     .addShutdownHook(new Thread("wdm-shutdown-hook") {
                         @Override

src/main/java/io/github/bonigarcia/wdm/config/Config.java

@@ -83,6 +83,8 @@ public class Config {
             "wdm.avoidReadReleaseFromRepository", Boolean.class);
     ConfigKey<Boolean> avoidTmpFolder = new ConfigKey<>("wdm.avoidTmpFolder",
             Boolean.class);
+    ConfigKey<Boolean> avoidShutdownHook = new ConfigKey<>(
+            "wdm.avoidShutdownHook", Boolean.class);
     ConfigKey<Integer> timeout = new ConfigKey<>("wdm.timeout", Integer.class);
     ConfigKey<Boolean> versionsPropertiesOnlineFirst = new ConfigKey<>(
             "wdm.versionsPropertiesOnlineFirst", Boolean.class);
@@ -540,6 +542,15 @@ public Config setAvoidTmpFolder(boolean value) {
         return this;
     }
 
+    public boolean isAvoidShutdownHook() {
+        return resolve(avoidShutdownHook);
+    }
+
+    public Config setAvoidShutdownHook(boolean value) {
+        this.avoidShutdownHook.setValue(value);
+        return this;
+    }
+
     public int getTimeout() {
         return resolve(timeout);
     }

src/main/resources/webdrivermanager.properties

@@ -9,6 +9,7 @@ wdm.avoidResolutionCache=false
 wdm.avoidFallback=false
 wdm.avoidReadReleaseFromRepository=false
 wdm.avoidTmpFolder=false
+wdm.avoidShutdownHook=false
 wdm.timeout=30
 wdm.resolutionCache=resolution.properties
 wdm.ttl=86400