Add Graphs

[Gabrielboudreau]

Add visuals for the statistical data

• [x] Histogram (Generated)
• [x] Histogram (Used in database)
• [x] Dotplot (Generated)
• [x] Dotplot (Used in database)
• [x] Boxplot (Generated)
• [x] Boxplot (Used in database)
• [x] Stemgraph (Generated)
• [x] Stemgraph (Used in database)

[rjawesome]

See https://www.jfree.org/jfreechart/api/javadoc/org/jfree/data/statistics/HistogramDataset.html & https://mvnrepository.com/artifact/jfree/jfreechart/1.0.13

[rjawesome]

Generated Histogram in Java. Still need to do some integration with API/exposing the image (in graphs branch)

[rjawesome]

Histogram should be done. Model can be followed for other graphs.

[rjawesome]

Histogram, Box Plot, Dot Plot Completed on respective Pull Requests. Still need to work on stem plot.

[rjawesome]

All graphs completed