Merge pull request #149 from spraints/release-assets-need-content-type-header

Set content-type for release assets

Octokit.Tests/Http/HttpClientAdapterTests.cs

@@ -74,6 +74,7 @@ namespace Octokit.Tests.Http
 
                 Assert.NotNull(requestMessage.Content);
                 Assert.IsType<StreamContent>(requestMessage.Content);
+                Assert.Equal("text/plain", requestMessage.Content.Headers.ContentType.MediaType);
             }
 
             [Fact]

Octokit/Http/HttpClientAdapter.cs

@@ -96,6 +96,7 @@ namespace Octokit.Internal
                 if (bodyStream != null)
                 {
                     requestMessage.Content = new StreamContent(bodyStream);
+                    requestMessage.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(request.ContentType);
                 }
             }
             catch (Exception)