Small fixes

build.gradle

@@ -11,9 +11,18 @@ repositories {
     jcenter()
 }
 
+jar {
+    manifest {
+        attributes "Main-Class": "tk.draganczuk.url.App"
+    }
+
+    from {
+        configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
+    }
+}
+
 dependencies {
 	compile "com.sparkjava:spark-core:2.8.0"
-    compile 'org.slf4j:slf4j-simple:1.7.21'
 }
 
 application {

src/main/java/tk/draganczuk/url/App.java

@@ -7,7 +7,7 @@ public class App {
 	public static void main(String[] args) {
 		// Useful for developing the frontend
 		// http://sparkjava.com/documentation#examples-and-faq -> How do I enable automatic refresh of static files?
-		if (System.getenv("dev").equals("true")) {
+		if (System.getenv("dev") != null) {
 			String projectDir = System.getProperty("user.dir");
 			String staticDir = "/src/main/resources/public";
 			staticFiles.externalLocation(projectDir + staticDir);