Enable pagination convention tests (#1659)

* Unskip pagination convention tests and rework exclusion property names
Also exclude Obsolete methods from pagination convention tests

* Reaction APIs appear to support pagination, flag to exclude for now and mark a TODO that they need implementing

* Repository invitation APIs need pagination implemented

* Exclude methods that use an alternative pagination approach

* Migrations, Licenses and References all need pagination implemented

* Pagination not supported for these methods (determined by API doc and poking the API) so exclude them from convention tests

* These methods need renaming to GetAll

* Rename offending RepositoryTrafficClient GetReferrers and GetPaths to GetAllReferrers and GetAllPaths

* Rename offending RepositoryBranchesClient methods from Get to GetAll

Octokit/Clients/IPullRequestReviewCommentReactionsClient.cs

@@ -18,6 +18,7 @@ namespace Octokit
         /// <param name="owner">The owner of the repository</param>
         /// <param name="name">The name of the repository</param>
         /// <param name="number">The comment id</param>        
+        [ExcludeFromPaginationApiOptionsConventionTest("TODO: Implement pagination for this method")]
         Task<IReadOnlyList<Reaction>> GetAll(string owner, string name, int number);
 
         /// <summary>
@@ -26,6 +27,7 @@ namespace Octokit
         /// <remarks>https://developer.github.com/v3/reactions/#list-reactions-for-a-pull-request-review-comment</remarks>
         /// <param name="repositoryId">The Id of the repository</param>
         /// <param name="number">The comment id</param>        
+        [ExcludeFromPaginationApiOptionsConventionTest("TODO: Implement pagination for this method")]
         Task<IReadOnlyList<Reaction>> GetAll(long repositoryId, int number);
 
         /// <summary>