Entirely remove Result type that not only is unneeded with Swift 5 but also was not being used by this library (it was left over from before Poly became its own library). Fix a few redundent public warnings.

Sources/JSONAPI/Result.swift

@@ -1,45 +0,0 @@
-//
-//  Result.swift
-//  JSONAPI
-//
-//  Created by Mathew Polzin on 12/5/18.
-//
-
-enum Result<T, E: Swift.Error> {
-	case success(T)
-	case failure(E)
-
-	var value: T? {
-		guard case .success(let val) = self else {
-			return nil
-		}
-		return val
-	}
-
-	var error: E? {
-		guard case .failure(let err) = self else {
-			return nil
-		}
-		return err
-	}
-
-	func map<U>(_ transform: (T) -> U) -> Result<U, E> {
-		switch self {
-		case .failure(let err):
-			return .failure(err)
-		case .success(let val):
-			return .success(transform(val))
-		}
-	}
-}
-
-extension Result: CustomStringConvertible where T: CustomStringConvertible, E: CustomStringConvertible {
-	var description: String {
-		switch self {
-		case .success(let val):
-			return String(describing: val)
-		case .failure(let err):
-			return String(describing: err)
-		}
-	}
-}