Commits per day should have a lengend + cumulative commits per day

[briandk]

This ultimately means two things:

1. Creating a cumulative commits per day plot
2. Adding a color legend

Consider this code from granovagg.1w.R in briandk/granovaGG/@9b70f3c24d241e3e31be25c94d88eedbd8eb93ba

GetColors <- function() {
  strokeColors <- c(
    "Grand Mean"         = brewer.pal(n = 8, name = "Set1")[3],
    "Group Mean Line"    = brewer.pal(n = 8, name = "Paired")[2],
    "Within 1 SDpooled"  = "darkblue",
    "Outside 1 SDpooled" = "darkorange"
  )

  fillColors <- c(
    "MS-between"         = GetMSbetweenColor(owp),
    "MS-within"          = GetMSwithinColor(owp),
    "Group Means"        = brewer.pal(n = 8, name = "Paired")[8]
  )
  return(list(stroke = strokeColors, fill = fillColors))
}

ColorScale <- function(owp) {
  output <- scale_color_manual(values = owp$colors$stroke, name = "")

  if(exists("guides")) {
    output <- scale_color_manual(
                values = owp$colors$stroke,
                name = "",
                guide = "legend"
              )
  }

  return(output)
}