Bump version to 1.5.1

bump version to 1.5.0

Merge branch 'develop'

Merge branch 'develop': v1.3.0. Safe kwargs for all AliceObjects

+ store raw json in models

Merge branch 'develop': v 1.2.5. Freeze attrs requirement

Merge branch 'develop': v 1.2.4. Update response timeout

Merge branch 'develop': v 1.2.3. Add new fields to interfaces + safe_…

…kwargs

Merge branch 'develop': v 1.2.2. Add original_request field to AliceR…

…equest

Add some hints about testing and deployment into README

Merge branch 'develop': v 1.2.1. Add interfaces.screen attr to Meta m…

…odel

Merge branch 'develop': v 1.2.0. Support NLU, safe_kwargs for meta an…

…d request (for future API updates compatability)