rivRmon v3.0.0

# Minor update to functions

* `swan_sufR` has been updated:
    + to replace the `swan_sufR_alt` function which has been removed.
    + to include minor adjustments to legend titles and legend bars to improve 
    aesthetics.
    + site SAND is now SANDBR in plots and it is expected to be called this in 
    the sonde data.
    + centred axis labels and added minor padding to the x axis to avoid 
    truncating labels.
    + top bin of colour scales in now a greater than ('>') category to accommodate 
    temperatures that exceed the existing scale.
    + response sites can now be included in the data and will be used as extra data 
    for interpolation, will appear in the plots in the water column but will not 
    be labelled (due to room limitations).
    
* `canning_sufR` has been updated:
    + to include minor adjustments to legend titles and legend bars to improve 
    aesthetics.
    + centred axis labels and added minor padding to the x axis to avoid 
    truncating labels.
    + top bin of colour scales in now a greater than ('>') category to accommodate 
    temperatures that exceed the existing scale.
    + response sites can now be included in the data and will be used as extra data 
    for interpolation, will appear in the plots in the water column but will not 
    be labelled.
    
# Update to internal data

* `sysdata`, which is only accessible to the package functions, has been updated:
    + to create bathymetry profile from newly updated origin shape files that now 
    contains site historical response sites.
    + to have new data breaks and labels to incorporate changes to the surfer plot 
    legends where the top bins are now a greater than ('>') category.
    
# A new function!

* `plot_metric` is a new function:
    + it draws on data from an edited excel workbook sheet that has BOTH sonde 
    data files appended and produces a single surfer style plot of any metric in the data.
    + the user will be prompted by the code for the metric they wish to plot.
    + the plots are intended as ad-hoc/quick looks at the data.