✨ Remove unused default headers & allow request specific headers

Sources/Hermes/Hermes.swift

@@ -81,14 +81,7 @@ public final class Hermes {
     }
     
     private var defaultHeaders: [String: String] {
-        var headers = [
-            "Content-Type": "application/json",
-            "Accept": "application/json"
-        ]
-        
-        headers.merge(config.defaultHeaders) { _, new in new }
-        
-        return headers
+        return config.defaultHeaders
     }
     
     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 = ["Custom-Header": "HeaderValue"]
+        let defaultHeaders = ["Content-Type": "application/json"]
         let decodingStrategy = JSONDecoder.KeyDecodingStrategy.convertFromSnakeCase
         let config = HermesConfiguration(defaultHeaders: defaultHeaders, decodingStrategy: decodingStrategy)
         Hermes.shared.configure(config)