Fix lint errors

Author: Ivan Kamkin

lib/src/api_client.dart

@@ -146,7 +146,7 @@ class ApiClient {
   }
 
   /// Invoke HTTP request
-  /// We don't use a Map<String, String> for queryParams.
+  /// We don't use a `Map<String, String>` for queryParams.
   /// If collectionFormat is 'multi' a key might appear multiple times.
   Future<Http.Response> invokeAPI(
       String path,

lib/src/model/code_location.dart

@@ -6,11 +6,11 @@ class CodeLocation {
 
   CodeLocation._internal(this._value);
 
-  // ignore: non_constant_identifier_names
+  // ignore: non_constant_identifier_names, public_member_api_docs
   static final CodeLocation Below = CodeLocation._internal("Below");
-  // ignore: non_constant_identifier_names
+  // ignore: non_constant_identifier_names, public_member_api_docs
   static final CodeLocation Above = CodeLocation._internal("Above");
-  // ignore: non_constant_identifier_names
+  // ignore: non_constant_identifier_names, public_member_api_docs
   static final CodeLocation None = CodeLocation._internal("None");
 
   /// Creates a CodeLocation instance from a JSON representation.