[#32] Add stability level override

Author: spyrkob

src/main/java/org/wildfly/installationmanager/spi/InstallationManagerFactory.java

@@ -33,6 +33,16 @@ public interface InstallationManagerFactory {
      */
     InstallationManager create(Path installationDir, MavenOptions mavenOptions) throws Exception;
 
+    /**
+     * Creates InstallationManger for server instance located at {@code installationDir}.
+     * If the provided directory is empty, the manger needs to install the server before attempting any other operations.
+     *
+     * @param installationDir the directory where the server is installed
+     * @param mavenOptions    the options to be used by the manager
+     * @return the InstallationManager instance
+     */
+    InstallationManager create(Path installationDir, MavenOptions mavenOptions, Stability stability) throws Exception;
+
     /**
      * Gets the name of InstallationManager instance
      *

src/main/java/org/wildfly/installationmanager/spi/Stability.java

@@ -0,0 +1,5 @@
+package org.wildfly.installationmanager.spi;
+
+public enum Stability {
+    Experimental, Preview, Community, Default
+}