v0.1.2

Improvements:

• Balance Formula in Expression Conversion (#7) by @maennchen (#7)

• Exhaustive Expression.expand/2 short-circuits (#5) by @maennchen (#5)

• enhance idempotent law to handle nested expressions (#6) by @zachdaniel (#6)

• Remove CommutativityLaw in Simplify (#4) by @maennchen (#4)

• Improve SAT Implementations in Testing (#3) by @maennchen (#3)