Allow for conjunction between logical expressions

[smkatz12]

Add functionality to make the following work:

@formula □(s->s[1] < 50 && s[4] < 1)

Thanks!

[mossr]

Now it works as expected:

ϕ = @formula □(s->s[1] < 50 && s[4] < 1)
ϕ([(49, 0, 0, 0), (49, 0, 0, -1)]) # returns true.
# Note this input can be an Array{Array}, Array{Tuple}, Tuple{Array}, or Tuple{Tuple}.
end