v0.3.0

SymbolicControlSystems v0.3.0

Diff since v0.2.0

• Breaking change: (affecting undocumented by often used function) conversion to Num is now done with to_num instead of Num to prevent inference failures.
• bug fixes.

Merged pull requests:

• handle MIMO sys in Num conversion (#24) (@baggepinnen)
• handle conversion from number to Sym tf (#25) (@baggepinnen)