Mcplot

* Added 'order' keyword to `get_cmap`.

* Changed order of color maps in printing and plotting.
* Edited docstrings of color module to follow closer numpydoc.

* Use `text2plot` in `abc2plot` and `signature2plot`.
* Better handling of linebreaks in Matplotlib and LaTeX mode in `str2tex`.
* Added `text2plot`, adding text onto a plot.
* Added `int2roman` and `roman2int`, converting integer to and from
Roman literals.
* Combine `abc2plot` and `signature2plot` in one file `text2plot.py`.
* Added `abc2plot`, adding a, B, iii), etc. onto a plot.
* Added `signature2plot`, adding a copyright notice onto a plot.
* Added 'pyjams_color.pdf' as reference to available colormaps.

* Added tests for `color`.
* Added 'pragma: no cover' to plot and MPI sections of codes so that they
are not included in coverage report.
* Cleaned mcPlot docstrings.
* Added current colors of Paul Tol, i.e. sron color palettes.

* Add `position`, which positions arrays of subplots to be used with
Matplotlib's add_axes.

* Write standard output file of mcPlot into current folder.
* Add `str2tex`, converting strings to LaTeX strings
* Added `color`, a collection of color palettes and continuous color maps.