v0.2.0

Thanks all for the feedbacks!

• A new function, pre.rotate has been introduced so that both trees tips can be ordered so that the cophylogeny connections can be compared easily. This function uses cophylo from phytools.
• Also, new co-phylogeny function common.tanglegram has been introduced which can connect all common tips between both trees.
• The connections can be colored by categories by providing custom color or by generating random colors in both simple.tanglegram or common.tanglegram.