Release v0.10.0

Release v0.10.0

Highlights

• Refactor the plotting library for better UX and consistency with pandas,
  matplotlib and seaborn.
• Add a sankey() feature to the plotting library.
• Rework the documentation and tutorials.

API changes

Several PRs in this release changed the implementation of the plotting library
for better UX and consistency with pandas, matplotlib and seaborn.

Replace the calls to plotting features by the following:

• plot(...) (or plot(kind='line', ...)) for line_plot()
• plot.stack(...) for stack_plot()
• plot.bar() for bar_plot()
• ...

These PRs also add an order arg to the plotting functions, and the levels
are ordered based on the run_control()['order'] dictionary by default.

Individual updates

• #475 Add a scatter plot example to the gallery
• #473 Refactor to plotting API following pandas/matplotlib implementation
• #472 Add a sankey() example to the plotting gallery
• #470 Add two types of order arg to barplot()
• #467 Refactor the GAMS-pyam tutorial to use the gamstransfer module
• #466 Add a sankey() function to create sankey diagrams
• #464 Add order arg to stackplot()
• #463 Clarification of initialization-error message if file does not exist