Repeated Ignore Warning Block in Tests

A number of tests have the same ignore warning block:

```
@pytest.mark.filterwarnings("ignore:Input shape must be 1D")
@pytest.mark.filterwarnings("ignore:This function assumes shape is 2D")
@pytest.mark.filterwarnings("ignore:Input shape must be 4D")
@pytest.mark.filterwarnings("ignore:Input shape must be 5D")
```
We may be able to tidy this up into an import block throughout.