Unit tests use remote API instance

[pnorman]

A number of tests in APITests.cs interact with api06.dev.openstreetmap.org. This is an issue for a few reasons

• The test API isn't really designed for unit tests. About half the changesets on it are now from osmsharp
• The credentials used are hard-coded in the source code. Anyone could change the password
• OAuth is not used, nor does it appear to be tested. OAuth should be the standard
• Unit tests shouldn't interact with external services, particularly those outside the developers control. This makes the unit tests no longer a unit test, but a test of the external service as well. Instead, the external service should be mocked up

[xivk]

Couldn't agree more, already removed the tests!

Rest of the remarks make sense but it may be better to remove everything related to talking to the OSM-API instead of making the effort to update.