Update Optim requirement from 1.4.1 to 1.4.1, 2.0

Updates the requirements on [Optim](https://github.com/JuliaNLSolvers/Optim.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaNLSolvers/Optim.jl/releases)
- [Changelog](https://github.com/JuliaNLSolvers/Optim.jl/blob/master/NEWS.md)
- [Commits](JuliaNLSolvers/Optim.jl@v1.4.1...v2.0.1)

---
updated-dependencies:
- dependency-name: Optim
  dependency-version: 2.0.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Project.toml

@@ -28,7 +28,7 @@ DataFrames = "1.2.2"
 FillArrays = "1"
 LabelledArrays = "1.6.5"
 Missings = "1.0.2"
-Optim = "1.4.1"
+Optim = "1.4.1, 2.0"
 PaddedViews = "0.5.10"
 Parameters = "0.12.3"
 Pipe = "1.3"