Add missing using DataFrames (#75)

* Add missing `using DataFrames`

* Update Project.toml

Author: tmigot

tutorials/introduction-to-bundleadjustmentmodels/Project.toml

@@ -5,5 +5,5 @@ NLPModels = "a4795742-8479-5a88-8948-cc11e1c8c1a6"
 
 [compat]
 BundleAdjustmentModels = "0.3.1"
-DataFrames = "1"
+DataFrames = "~1.3"
 NLPModels = "0.19"

tutorials/introduction-to-bundleadjustmentmodels/index.jmd

@@ -7,7 +7,7 @@ author: "Antonin Kenens and Tangi Migot"
 A Julia repository of [bundle adjustment](https://en.wikipedia.org/wiki/Bundle_adjustment) problems from the [Bundle Adjustment in the Large](http://grail.cs.washington.edu/projects/bal/) repository.
 
 ```julia
-using BundleAdjustmentModels
+using BundleAdjustmentModels, DataFrames
 ```
 
 ## Get the list of problems