flow_compose 0.0.1+4

flow chart for flutter (FOR FUN).

0.0.1+4

• make INode not abstract.
• add toJson and fromJson

0.0.1+3

• add some example, fix errors.

0.0.1+2

• Introduce INode.

0.0.1+1

• Fix and new features.

0.0.1

• initial release.