Fixed DoesOrgExist to not retry when org exists (#952)

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Fixes #944 

`GithubApi.DoesOrgExist()` was working, but it was unnecessarily
retrying 5 times when the org did exist before finally returning the
correct response of `true`.

It was likely written this way because it was copied from the
implementation of `DoesRepoExist()`.

The difference is when we check for the existence of the target repo we
expect it to NOT exist (and if it does that API call will get retried 5
times probably unnecessarily, but should be rare enough that it's fine).
But when checking for the target org we expect that it DOES exist, and
don't want to retry in the case of success.

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RELEASENOTES.md

@@ -1 +1 @@
-
+- Fixed a bug when migrating from GHES where we would do a bunch of unnecessary retries at the start making things slower than they needed to be

src/Octoshift/Services/GithubApi.cs

@@ -125,12 +125,12 @@ public virtual async Task<bool> DoesOrgExist(string org)
         var url = $"{_apiUrl}/orgs/{org.EscapeDataString()}";
         try
         {
-            await _client.GetNonSuccessAsync(url, HttpStatusCode.NotFound);
-            return false;
+            await _client.GetAsync(url);
+            return true;
         }
-        catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.OK)
+        catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
         {
-            return true;
+            return false;
         }
     }
 

src/OctoshiftCLI.Tests/Octoshift/Services/GithubApiTests.cs

@@ -348,12 +348,12 @@ await FluentActions
     }
 
     [Fact]
-    public async Task DoesTargetOrgExist_Returns_True_When_200()
+    public async Task DoesOrgExist_Returns_True_When_200()
     {
         // Arrange
         var url = $"https://api.github.com/orgs/{GITHUB_ORG}";
 
-        _githubClientMock.Setup(m => m.GetNonSuccessAsync(url, HttpStatusCode.NotFound)).ThrowsAsync(new HttpRequestException(null, null, HttpStatusCode.OK));
+        _githubClientMock.Setup(m => m.GetAsync(url, null)).ReturnsAsync("OK");
 
         // Act
         var result = await _githubApi.DoesOrgExist(GITHUB_ORG);
@@ -363,12 +363,12 @@ public async Task DoesTargetOrgExist_Returns_True_When_200()
     }
 
     [Fact]
-    public async Task DoesTargetOrgExist_Returns_False_When_404()
+    public async Task DoesOrgExist_Returns_False_When_404()
     {
         // Arrange
         var url = $"https://api.github.com/orgs/{GITHUB_ORG}";
 
-        _githubClientMock.Setup(m => m.GetNonSuccessAsync(url, HttpStatusCode.NotFound)).ReturnsAsync("Not Found");
+        _githubClientMock.Setup(m => m.GetAsync(url, null)).ThrowsAsync(new HttpRequestException(null, null, HttpStatusCode.NotFound));
 
         // Act
         var result = await _githubApi.DoesOrgExist(GITHUB_ORG);
@@ -378,12 +378,12 @@ public async Task DoesTargetOrgExist_Returns_False_When_404()
     }
 
     [Fact]
-    public async Task DoesTargetOrgExist_Throws_On_Unexpected_Response()
+    public async Task DoesOrgExist_Throws_On_Unexpected_Response()
     {
         // Arrange
         var url = $"https://api.github.com/orgs/{GITHUB_ORG}";
 
-        _githubClientMock.Setup(m => m.GetNonSuccessAsync(url, HttpStatusCode.NotFound)).ThrowsAsync(new HttpRequestException(null, null, HttpStatusCode.Unauthorized));
+        _githubClientMock.Setup(m => m.GetAsync(url, null)).ThrowsAsync(new HttpRequestException(null, null, HttpStatusCode.Unauthorized));
 
         // Act
         await FluentActions