Add PipelineStatus.Manual (#147)

Author: mberginbh

src/GitLabApiClient/Models/Pipelines/PipelineStatus.cs

@@ -23,5 +23,7 @@ public enum PipelineStatus
         Scheduled,
         [EnumMember(Value = "created")]
         Created,
+        [EnumMember(Value = "manual")]
+        Manual,
     }
 }