added env variable and java properties substitution in configuration attributes

gbcs-api/src/main/java/net/woggioni/gbcs/api/exception/ConfigurationException.java

@@ -0,0 +1,11 @@
+package net.woggioni.gbcs.api.exception;
+
+public class ConfigurationException extends GbcsException {
+    public ConfigurationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ConfigurationException(String message) {
+        this(message, null);
+    }
+}