Profiled units

[hejun0524]

src/UnitCommitment.jl

• Added the source code file for profiled units (src/model/formulations/base/punit.jl).

src/instance/migrate.jl

• Added migration to 0.4.

src/instance/read.jl

• Changed the generator units part to identify the Type attribute and include profiled units.

src/instance/structs.jl

• Added the structs for profiled units, changed the bus and instance to include profiled units.

src/model/build.jl

• Added a for-loop to build the optimization model of the profiled units part, calls the function defined in punit.jl file below.

src/model/formulations/base/punit.jl

• Created this file to append a profiled unit to the optimization model (decision variables, constraints and objective function).

test/instance/migrate_test.jl

• Added test case for migration to 0.4.
• Note that in Fixture, a file with name ucjl-0.4.json.gz is added.

test/instance/read_test.jl

• Added test case for reading.
• It seems that case14.json.gz is solved somewhere else and if the profiled units are added those results may change.
• Instead I created a new file named case14-profiled.json.gz. I added two more generators into the file (and I think ucjl-0.3.json.gz and case14.json.gz are related, if so, then ucjl-0.4 and case14-profiled should also be related.)
• The test case uses exactly the same code as the first read_benchmark test case, with an additional check on the number of profiled units (==2) and an additional check on whether the code reads the second profiled unit correctly.