…removed duplicate code in dabest_object file

… not in order with the dataframe itself

… groups

…tom_pal should now work with all types of plots

> Changed mini_meta attribute to is_mini_meta to better fit with other attributes (such as is_paired and is_proportional)
> Changed mini_meta_delta class to mini_meta to better fit with other attributes such as delta_delta

…s. Also added an is_delta_delta property

> Trim down repeated code by creating a new function to pick the color for the contrast/swarm/summary bars
> added an is_delta_delta property

> Fix capitalisations and naming terminology (E.g., using Hedges' g now instead of hedges g)
> Major edits to forestplot - removing excess code, removing redundant code, tidying up functions, adding extra error checks, edit some functionality
> fixed some incorrect image tests
> Removed the delta_g dabest attribute and shifted it to hedges_g to better fit the theme of the package
> Fixed functionality where delta2=True and effect_size is not hedges_g or mean_diff but it still generates delta_g data (not supposed to happen)
> updated some code that will be redundant in future python version (~isinstance)

…o one function

> Trimmed excess code
> Created one function to be used for plotting both the swarm bars and contrast bars
>tidied up some code snippets and layout of the plotter code

…to use hedges_g when delta2=True