v 0.7.0

• Add Block state to store data private to the block. Using block.get_state('key'), block.set_state('key').
• Block state also stores execution status and errors. Using block.get_state('info'), block.set_state('info'). Note: 'info' is a reserved key.
• When a block fails on its compute function, its descendants are skipped and the rest of the blocks are computed.
• Add delete schema function. (@zabrewer)

0.6.1

• Add option to categories the Blocks with a category in a sub-menu in the context menu on right-click>add-node.
• Fix compute_engine to take in categories.

0.6.0

• Add option to categories the Blocks with a category in a sub-menu in the context menu on right-click>add-node.