✨ Remove unused default headers & allow request specific headers

Sources/Hermes/Hermes.swift

@@ -81,7 +81,14 @@ public final class Hermes {
     }
     
     private var defaultHeaders: [String: String] {
-        return config.defaultHeaders
+        var headers = [
+            "Content-Type": "application/json",
+            "Accept": "application/json"
+        ]
+        
+        headers.merge(config.defaultHeaders) { _, new in new }
+        
+        return headers
     }
     
     public func load<T: Codable>(_ resource: Resource<T>) async throws -> T {

Tests/HermesTests/HermesTests.swift

@@ -8,7 +8,7 @@ final class HermesTests: XCTestCase {
     }
     
     private func configureHermes() {
-        let defaultHeaders = ["Content-Type": "application/json"]
+        let defaultHeaders = ["Custom-Header": "HeaderValue"]
         let decodingStrategy = JSONDecoder.KeyDecodingStrategy.convertFromSnakeCase
         let config = HermesConfiguration(defaultHeaders: defaultHeaders, decodingStrategy: decodingStrategy)
         Hermes.shared.configure(config)