feat: getting a template from a URL (refs tomasbjerre#184)

src/main/java/se/bjurr/gitchangelog/internal/util/ResourceLoader.java

@@ -5,6 +5,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.net.URL;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -30,6 +31,9 @@ public static String getResourceOrFile(final String resourceName, final Charset
               getResourceFromClassLoader(
                   resourceName, Thread.currentThread().getContextClassLoader());
         }
+        if (inputStream == null) {
+          inputStream = getResourceFromURL(resourceName);
+        }
 
         if (inputStream == null) {
           throw new FileNotFoundException(
@@ -61,4 +65,13 @@ private static InputStream getResourceFromClassLoader(
     }
     return inputStream;
   }
-}
+
+  private static InputStream getResourceFromURL(final String resourceName) {
+    try {
+      URL url = new URL(resourceName);
+      return url.openStream();
+    } catch (IOException e) {
+      return null;
+    }
+  }
+}