Black Friday purchase analysis v4.0 (final)

This new release included a Dockerfile, which can help people quickly "clone" a computing environment used for this project and run all the scripts without installing all related software packages.
This release also made some updates on Makefile and added a dependency diagram, along with some other small improvements.

Black Friday purchase analysis automated by Make

Added Makefile to automate the execution of the data analysis work in this project. Also made some updates on documents and scripts based on feedback collected.

Black Friday purchase analysis v2.1

We now finished the data analysis work for this project. Included in this release are all the documents related, including four R scripts, tidy data, figures generated from exploratory data analysis, outputs from formal analysis, an R Markdown report and a rendered Markdown report file. We also made an update to the project in response to the feedback from Ali. The proposal is moved to doc folder.

Black Friday purchase analysis v1.0

We included in this release a final version of the project proposal, which explains the data set that will be used in analysis, the objective of this project, analysis plan and what the final summary presentation may look like.