Relative paths in hypes

[MartinThoma]

Currently, relative paths in hypes have to get handled by every single script. This is an issue, because we (or the people using the loaded hypes dict) could simply forget that the relative paths are not relative to the hypes.json file, but relative to the calling Python script.

We handled those here:

• https://github.com/TensorVision/TensorVision/blob/master/tensorvision/utils.py#L54
• https://github.com/TensorVision/TensorVision/blob/master/tensorvision/utils.py#L129
• https://github.com/TensorVision/TensorVision/blob/master/tensorvision/utils.py#L156
• https://github.com/TensorVision/TensorVision/blob/master/tensorvision/train.py#L56
• probably more

I suggest to automatically make paths absolute in the hypes loading function (see #52). For example, we could say that each key which ends with _path will be made absolute if it is relative.

[MarvinTeichmann]

Sounds like a good idea!

[MarvinTeichmann]

Just saw an issue with this approach: What kind of data should be loaded depends on the content. I.e. data is assumed to be relative to TV_PATH_DATA, while models should be defined relative to hypes file.