v0.2.0

Added

• Add sub-hourly unit commitment.
• Add UnitCommitment.write(filename, solution).
• Add mathematical formulation to the documentation.

Changed

• Rename "Time (h)" parameter to "Time horizon (h)".
• Rename UnitCommitment.get_solution to UnitCommitment.solution, for better
  consistency with JuMP style.
• Add an underscore to the name of all functions that do not appear in the
  documentation (e.g. something becomes _something) These functions are not
  part of the public API and may change without notice, even in PATCH releases.
• The function UnitCommitment.build_model now returns a plain JuMP model. The
  struct UnitCommitmentModel has been completely removed. Accessing model
  elements can now be accomplished as follows:
  • model.vars.x[idx] becomes model[:x][idx]
  • model.eqs.y[idx] becomes model[:eq_y][idx]
  • model.expr.z[idx] becomes model[:expr_z][idx]
  • model.obj becomes model[:obj]
  • model.isf becomes model[:isf]
  • model.lodf becomes model[:lodf]

Fixed

• Properly validate solutions with price-sensitive loads.