Release 1.5.3

fix: quick fix for netatmo api changes

Extend CredentialManager to accept refresh_token and add warning message
for deprecated GenerateToken

Example usage:

```csharp
var clientId = "myClientId";
var clientSecret = "myClientSecret";
var accessToken = "myAccessToken";
var refreshToken = "myRefreshToken";

var client = new Client(
    SystemClock.Instance, "https://api.netatmo.com/",
    clientId,
    clientSecret);

client.ProvideOAuth2Token(accessToken, refreshToken);
await client.RefreshToken();
var stationsData = await client.Weather.GetStationsData();
```

Refs: #167 #168