Added PUT Update LAN Coordinates endpoints, added tests for it

[IvanKolchanov]

Resolves #322
@marcin-krystianc

[marcin-krystianc]

Left some suggestions

[marcin-krystianc]

I think we also need a variant with WriteOptions

[marcin-krystianc]

I'm not a fan of that loop.
I think there is a reliable way to query the node without using the loop.
You can use so called "blocking queries", i.e.: use query options with a non-zero wait-index:

   await _client.Catalog.Register(registration);
   var nodeResult = await _client.Catalog.Node(nodeName);
   Assert.Equal(HttpStatusCode.OK, nodeResult.StatusCode);
...
   await _client.Coordinate.Update(coord);
...
   var q = new QueryOptions{ WaitIndex = nodeResult.LastIndex, };
   var newCoordResult = await _client.Coordinate.Node(nodeName, q);
   Assert.Equal(HttpStatusCode.OK, response.StatusCode);

I tried this locally and it seemed working reliably.

[IvanKolchanov]

That's fair, there wasn't really a similar situation in the previous code, so I went for something similar to Golang code's retry loop. Should we change waitTime to around 10 seconds, to avoid hanging for the default 5 minutes? And I have a little question, I am a bit confused on how is the index of node registered in catalog connected to the coordinate node? I am still working on my familiarity with all consul features, sorry.

[marcin-krystianc]

No worries, it is sometimes a bit of unknown for me as well 😄 I'm concerned about the loop because it introduces a risk of flakiness. We run each test many times (we have a matrix with os, consul version and runtime version), thus we need to have really robust tests.
I think the "LastIndex"/"WaitIndex" are global, so it doesn't matter that they are from different endpoints.

Should we change waitTime to around 10 seconds, to avoid hanging for the default 5 minutes
I think it is better to wait longer, but have more robust tests. Therefore I wouldn't change the default waitTime.

[IvanKolchanov]

Thanks!) Makes sense, I will commit all the changes and we see how the tests go.

[marcin-krystianc]

FYI: I've just updated my code snipped from above, to make it clear that the Catalog.Node() call should be before the Coordinate.Update() call.

[IvanKolchanov]

@marcin-krystianc

Left some suggestions

Okey, everything should be good

[marcin-krystianc]

Nice 👍

[marcin-krystianc]

PS: I think you need to push some dummy changes, so the last commit is not from whitespace fixing bot. Otherwise, It is impossible to merge it.