Bump required julia version

Switch to Project.toml

* switch from require to project.toml

* add to project.toml

* set random seed in tests

Update deps

v0.3.1

Delete Project.toml

Julia v1.0

Some breaking changes

• keyword alpha -> α
• See files included in runtests.jl for current usage

Updates for Julia v0.6

v0.2.0

DifferentialDynamicProgramming v0.2.0 [1a3f3e5635]

Updates for plots

Updates for plots and ControlSystems.jl