v0.2.0

Added

• Contributed initial build of R package.
• Added access to cytoscape.js PNG and JPG image generation API through generateImage and
  imageData properties (PR #88).
• Added ability to download image files generated with generateImage client-side without sending
  data to the server (PR #88).
• Used the newly added generateImage and imageData properties to enable svg generation using cytoscape-svg.
• Added responsive cytoscape.js graph feature toggled using the responsive property (PR #93).
• One new demo:
  • demos/usage-responsive-graph.py: Example of graph with the ability to toggle the responsive feature on and off.
  • demos/usage-image-export.py: Shows how to export images as JPG, PNG or SVG.

Changed

• Changed the official package manager from yarn to npm.
• utils.Tree: v0.1.1 broke compatibility with Python 2. Therefore, modified code to be compatible
  with Python 2. Added props and edge_props properties to accept arguments passed directly to
  the node's and edge's dictionaries, respectively (e.g., 'classes', 'positions', etc.).
• Removed Tree's method add_child, because it is redundant with add_children called with an
  argument of length 1.
• setup.py: Remove dash-html-components and dash_renderer from install_requires.
• usage-events.py: Fix the size of the cytoscape graph to 500px by 500px.
• Upgrade react-cytoscape.js to latest.

Fixed

• setup.py: Use packages=find_packages(include=[package_name, package_name + ".*"]) so that all
  subpackages like utils will be included when you pip install dash-cytoscape.
• Issue where dash-cytoscape cannot read property of 'length' of undefined when elements is not specified.
• tests.test_interactions.