Fixes #54 Swallows exceptions on getting extra github data

It's ok to swallow these exceptions because the data is not necessary
for correct execution of the code.
Somehow I ended up having username "Test" in my test setup, and here's the exception I've got when it tried to update data for Test's repository "AMS":

{Octokit.NotFoundException: Not Found
   at Octokit.Connection.HandleErrors(IResponse response)
   at Octokit.Connection.<RunRequest>d__18`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at Octokit.Connection.<Run>d__14`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at Octokit.ApiConnection.<Get>d__0`1.MoveNext()}


So this fix protects not only from not being able to reach GitHub, but errors from GitHub API: either because the username/repo we specify is incorrect, or for a wealth of other reasons