Add "About the company" section (#161)

* modified:   sklift/tests/test_metrics.py

* deleted:    sklift/tests/test_plot_qini_curve.py
	deleted:    sklift/tests/test_plot_uplift_curve.py
	new file:   sklift/tests/test_viz.py

* modified:   docs/api/datasets/fetch_criteo.rst
	modified:   docs/api/datasets/fetch_hillstrom.rst
	modified:   docs/api/datasets/fetch_lenta.rst
	modified:   docs/api/datasets/fetch_megafon.rst
	modified:   docs/api/datasets/fetch_x5.rst

* modified:   docs/api/datasets/fetch_criteo.rst
	modified:   docs/api/datasets/fetch_hillstrom.rst
	modified:   docs/api/datasets/fetch_lenta.rst
	modified:   docs/api/datasets/fetch_megafon.rst
	modified:   docs/api/datasets/fetch_x5.rst

Author: flashlight101

docs/api/datasets/fetch_criteo.rst

@@ -6,4 +6,17 @@
 
 .. autofunction:: sklift.datasets.datasets.fetch_criteo
 
+About the company
+##################
+
+Criteo is an advertising company that provides online display advertisements. 
+The company was founded and is headquartered in Paris, France. Criteo's product is a form of display advertising, 
+which displays interactive banner advertisements, generated based on the online browsing preferences and behaviour for each customer. 
+The solution operates on a pay per click/cost per click (CPC) basis.
+
+.. figure:: https://upload.wikimedia.org/wikipedia/commons/d/d2/Criteo_logo21.svg
+
+Link to the company's website: https://www.criteo.com/
+
+
 .. include:: ../../../sklift/datasets/descr/criteo.rst

docs/api/datasets/fetch_hillstrom.rst

@@ -6,4 +6,12 @@
 
 .. autofunction:: sklift.datasets.datasets.fetch_hillstrom
 
+About the company
+##################
+
+The dataset was provided by Kevin Hillstorm. 
+Kevin is President of MineThatData, a consultancy that helps CEOs understand the complex relationship between Customers, Advertising, Products, Brands, and Channels.
+
+Link to the blog website: https://blog.minethatdata.com/
+
 .. include:: ../../../sklift/datasets/descr/hillstrom.rst

docs/api/datasets/fetch_lenta.rst

@@ -6,4 +6,14 @@
 
 .. autofunction:: sklift.datasets.datasets.fetch_lenta
 
+About the company
+##################
+
+Lenta (Russian: Лентa) is a Russian super - and hypermarket chain. With 149 locations across the country, 
+it is one of Russia's largest retail chains in addition to being the country's second largest hypermarket chain.
+
+.. figure:: https://upload.wikimedia.org/wikipedia/commons/7/73/Lenta_logo.svg
+
+Link to the company's website: https://www.lenta.com/
+
 .. include:: ../../../sklift/datasets/descr/lenta.rst

docs/api/datasets/fetch_megafon.rst

@@ -6,4 +6,14 @@
 
 .. autofunction:: sklift.datasets.datasets.fetch_megafon
 
+About the company
+##################
+
+MegaFon (Russian: МегаФон), previously known as North-West GSM, is the second largest mobile phone operator and the third largest telecom operator in Russia. 
+It works in the GSM, UMTS and LTE standard. As of June 2012, the company serves 62.1 million subscribers in Russia and 1.6 million in Tajikistan. It is headquartered in Moscow.
+
+.. figure:: https://upload.wikimedia.org/wikipedia/commons/9/9e/MegaFon_logo.svg
+
+Link to the company's website: https://megafon.ru/
+
 .. include:: ../../../sklift/datasets/descr/megafon.rst

docs/api/datasets/fetch_x5.rst

@@ -6,4 +6,16 @@
 
 .. autofunction:: sklift.datasets.datasets.fetch_x5
 
+About the company
+##################
+
+X5 Group is a leading Russian food retailer. 
+The Company operates several retail formats: proximity stores under the Pyaterochka brand, 
+supermarkets under the Perekrestok brand and hypermarkets under the Karusel brand, as well as the Perekrestok.ru online market, 
+the 5Post parcel and Dostavka.Pyaterochka and Perekrestok. Bystro food delivery services.
+
+.. figure:: https://upload.wikimedia.org/wikipedia/en/8/83/X5_Retail_Group_logo_2015.png
+
+Link to the company's website: https://www.x5.ru/
+
 .. include:: ../../../sklift/datasets/descr/x5.rst