Merge branch 'fix-daily-periods' into 'master'

Fix daily periods (value is not a field of type Date).

See merge request julia-packages/periods.jl!2

src/SimplePeriods.jl

@@ -44,8 +44,8 @@ function Period(arg1::Integer, arg2::Integer, arg3::Integer, frequency::Frequenc
     end
 end
 
-Period(year::Integer, month::Integer, day::Integer) = (Date(year, month, day).value, Day)
-Period(d::Date) = (d.value, Day)
+Period(year::Integer, month::Integer, day::Integer) =  (Date(year, month, day).instant.periods.value, Day)
+Period(d::Date) = (d.instant.periods.value, Day)
 
 import Base.copy
 copy(p::Period) = Period(p.ordinal, p.frequency)