v1.3.0

Features:

• Add smif CLI subcommands: decide, before_step, step
• Add --dry-run option when running a whole model run - prints a list of step subcommands
• Allow concrete instances of Model, SectorModel
• Include only sector_models and model_dependencies in job graphs (reduces logging noise)
• Include hundredths of a second in log timings

Fixes:

• Handle one-dimensional DataArray to Dataframe conversions (could mis-sort data with unordered
  labels in conversion to/from xarray - see pydata xarray #3798)
• Update npm dependencies
• Relax ruamel.yaml requirement to >=15.50
• Fix Travis/Appveyor tests under Python 3.5 (install/pin dependencies