v0.6.0

• The format of the horizontal line in the table, which are drawn using the option hlines, can now be selected using the keyword hlines_format.
• The alignment of a single cell can now be changed regardless of the column alignment. This can be achieve by the keyword cell_alignment.
• The line between the header and the data can now be hide using the variable header_line of the structure PrettyTableFormat. (Issue #15)
• New predefined highlighters: hl_cell, hl_col, hl_row, which can be used to apply highlights to single cells or to entire columns or rows, respectively.
• The formatter ft_printf is now only applied to cells that are of type Number. (Issue #19)
• The formatter ft_printf can now receive one integer if the user wants to format only a single column.
• End of support of Julia 1.1. The supported versions are 1.0 and 1.2.