Merge master into dotnetcore (#1599)

* bugfix - PUT should have a payload for Mark as Read (#1579)

* bugfix - PUT should have a payload for Mark as Read

* also fix the Observable client test

* add integration tests for MarkRead methods

* Fixup MarkReadForRepository methods to specify a body in the PUT request

* Fix unit tests for regular and observable client

* helps if the new files are included in the test project :)

* Cloning ApiInfo object should work when some fields are null (#1580)

* Adjust ApiInfo.Clone() to work even if some elements (eg ETag) are null

* Remove c# 6 language feature and do it the old school way

* Add a test for cloning ApiInfo when some fields are null

* The 3 lists can never be null anyway so remove some un-needed statements

* Add test for null RateLimit

* Remove Rx-Main dependency from samples
This resolves #1592 - LINQPad doesn't understand how to restore this unlisted package and it's not actually needed in the samples.

* Adding RemovedFromProject and other missing EventInfoState types. (#1591)

* Adding missing review types to event info.

* Fixing whitespace.

* Reword `BaseRefChanged` comment

* Adding missing event types.

* Change response models 'Url' properties from `Uri` to `string` (#1585)

* Add convention test to ensure 'Url' properties are of type string

Closes #1582

* Change 'Url' properties from Uri to string

Global Find/Replace FTW!

* fix compilation errors in the integration tests project

* Extend 'Url' properties type check to request models

* Stick to convention tests naming convention

* Remove unused using directives in models

Changing from `Uri` to `string` means the `using System;`
directive was not needed anymore in some files

* Update exception message wording

* empty commit to trigger a new build - hopefully Travis passes

* add convention test to ensure request models have Uri 'Url' properties

* make request models 'Url' properties Uri

fix typo in convention test name

* revert some request models 'Url' properties as `string`

see https://github.com/octokit/octokit.net/pull/1585#issuecomment-297186728

* Change test so that all model types must have 'Url' properties of type string

 - Filter test input to only get types which have 'Url' properties
 - Merge response and request model types tests into one
 - Unparameterize the exception since we only check for the string type now

* Fix string.Format tokens

If this PR doesn't get rebased, it'll be my wall of shame FOREVER!

* and then it's even more embarrassing when the commit message says rebased but you really meant squashed

* Remove exclusion of `Release` from request models

Octokit/Models/Response/GistComment.cs

@@ -9,7 +9,7 @@ namespace Octokit
     {
         public GistComment() { }
 
-        public GistComment(int id, Uri url, string body, User user, DateTimeOffset createdAt, DateTimeOffset? updatedAt)
+        public GistComment(int id, string url, string body, User user, DateTimeOffset createdAt, DateTimeOffset? updatedAt)
         {
             Id = id;
             Url = url;
@@ -27,7 +27,7 @@ namespace Octokit
         /// <summary>
         /// The URL for this gist comment.
         /// </summary>
-        public Uri Url { get; protected set; }
+        public string Url { get; protected set; }
 
         /// <summary>
         /// The body of this gist comment.