deprecated with Julia nightly

[scls19fr]

From https://travis-ci.org/scls19fr/ExtensibleScheduler.jl/jobs/322100417

WARNING: Base.Pkg is deprecated, run `using Pkg` instead
 in module Main
WARNING: Base.Pkg is deprecated, run `using Pkg` instead
 in module Main
   Testing ExtensibleScheduler
 Resolving package versions...
┌ Warning: Deprecated syntax `multiple line breaks between doc string and object` at /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:44.
│ Use `at most one line break` instead.
└ @ nothing time.jl:44
┌ Warning: Deprecated syntax `multiple line breaks between doc string and object` at /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:46.
│ Use `at most one line break` instead.
└ @ nothing time.jl:46
WARNING: importing deprecated binding Base.now into ExtensibleScheduler.
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
WARNING: importing deprecated binding Base.Dates into ExtensibleScheduler.
WARNING: Base.Dates is deprecated, run `using Dates` instead
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
WARNING: Base.Dates is deprecated, run `using Dates` instead
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl:21
in Type at /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/time.jl
WARNING: importing deprecated binding Base.now into ExtensibleScheduler.
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/rtclock.jl:17
WARNING: Base.now is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/clock/simclock.jl:10
WARNING: importing deprecated binding Base.iteratorsize into ExtensibleScheduler.
WARNING: Base.iteratorsize is deprecated, use IteratorSize instead.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/base.jl:24
WARNING: Base.iteratorsize is deprecated, use IteratorSize instead.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/base.jl:28
WARNING: importing deprecated binding Base.iteratorsize into ExtensibleScheduler.
WARNING: importing deprecated binding Base.DateTime into ExtensibleScheduler.
WARNING: Base.DateTime is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:3
WARNING: Base.DateTime is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:3
WARNING: Base.DateTime is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:3
WARNING: Base.iteratorsize is deprecated, use IteratorSize instead.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:12
WARNING: Base.DateTime is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:16
WARNING: Base.DateTime is deprecated: it has been moved to the standard library package `Dates`.
Add `using Dates` to your imports.
  likely near /home/travis/build/scls19fr/ExtensibleScheduler.jl/src/triggers/instant.jl:16