Development of CPUE figure

[MOshima-PIFSC]

I can work on developing code for the CPUE indices. I'm thinking of creating a simple plot_cpue() type function that plots one index and then a creating a wrapper function to plot all indices in one plot. Additionally, having a single plot with all indices on the same relative scale could be useful as well. This will be second priority.

Tasks:

• CPUE indices (D): Line graph with CIs for a single fleet
• Wrapper function to plot all at once
• One plot with all indices scaled