lasso, ridge, elastic net example (#420)

* lasso, ridge, elastic net example

* add LaTeXStrings

* added MOI

* Apply suggestions from code review

Co-authored-by: Soederlind <[email protected]>
Co-authored-by: Eric Hanson <[email protected]>

Author: PaulSoderlind

docs/Project.toml

@@ -8,9 +8,11 @@ Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 ECOS = "e2685f51-7e38-5353-a97d-a921fd2c8199"
 GLPK = "60bf3e95-4087-53dc-ae20-288a0d20c6a6"
 Interact = "c601a237-2ae4-5e1e-952c-7a85b0c7eef1"
+LaTeXStrings = "b964fa9f-0449-5b57-a5c2-d3ea65f4040f"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Literate = "98b081ad-f1c9-55d3-8b20-4c87d4299306"
 MAT = "23992714-dd62-5051-b70f-ba57cb901cac"
+MathOptInterface = "b8f27783-ece8-5eb3-8dc8-9495eed66fee"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 RDatasets = "ce6b1742-4840-55fa-b093-852dadbb1d8b"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
@@ -20,3 +22,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Documenter = "0.26"
+MathOptInterface = "~0.9"