Don't log files that dont load throw error instead

remove swift-log dependency

Sources/HummingbirdMustache/Library.swift

@@ -18,9 +18,9 @@ public final class HBMustacheLibrary {
     /// the folder is recursive and templates in subfolders will be registered with the name `subfolder/template`.
     /// - Parameter directory: Directory to look for mustache templates
     /// - Parameter extension: Extension of files to look for
-    public init(directory: String, withExtension extension: String = "mustache", logger: Logger? = nil) {
+    public init(directory: String, withExtension extension: String = "mustache") throws {
         templates = [:]
-        loadTemplates(from: directory, withExtension: `extension`, logger: logger)
+        try loadTemplates(from: directory, withExtension: `extension`)
     }
 
     /// Register template under name
@@ -49,5 +49,9 @@ public final class HBMustacheLibrary {
         return template.render(object)
     }
 
+    public enum Error: Swift.Error {
+        case failedToLoad(String, Swift.Error)
+    }
+
     private var templates: [String: HBMustacheTemplate]
 }