Support type `Hash`/`Array` for return value from ruby block

pry(main)> 'foo' | -> v { v.split('') } | -> v { puts v }
f
o
o
=> nil

pry(main)> '{ foo: "bar" }' | -> v { eval(v) } | -> v { puts v }
foo bar
=> nil
Update README
Bump to v0.0.4