Switch vim colorscheme to gruvbox (#23)

.config/nvim/colors/underwater.vim

@@ -0,0 +1,66 @@
+" Maintainer: Dmitry Kichenko (dmitrykichenko@gmail.com)
+" Last Change:	February 20, 2009
+
+set background=dark
+
+hi clear
+
+if exists("syntax_on")
+  syntax reset
+endif
+
+let colors_name = "underwater"
+
+" Vim >= 7.0 specific colors
+if version >= 700
+  " highlights current line
+  hi CursorLine guibg=#18374F
+  " cursor's colour
+  hi CursorColumn guibg=#ffffff
+  hi MatchParen guifg=#ffffff guibg=#439ea9 gui=bold
+  hi Pmenu 		guifg=#dfeff6 guibg=#1E415E
+  hi PmenuSel 	guifg=#dfeff6 guibg=#2D7889
+
+  " Search
+  hi IncSearch  gui=BOLD      guifg=#E2DAEF   guibg=#AF81F4
+  hi Search     gui=NONE   guifg=#E2DAEF   guibg=#AF81F4
+endif
+
+" General colors
+hi Cursor 		guifg=NONE    guibg=#55A096 gui=none
+hi Normal 		guifg=#dfeff6 guibg=#102235 gui=none
+ " e.g. tildes at the end of file
+hi NonText 		guifg=#96defa guibg=#122538 gui=none
+hi LineNr 		guifg=#2F577C guibg=#0C1926 gui=none
+hi StatusLine 	guifg=#96defa guibg=#0C1926 gui=italic
+hi StatusLineNC guifg=#68CEE8 guibg=#0C1926  gui=none
+hi VertSplit 	guifg=#1A3951 guibg=#1A3951 gui=none
+hi Folded 		guifg=#68CEE8 guibg=#1A3951 gui=none
+hi FoldColumn   guifg=#1E415E guibg=#1A3951 gui=none
+hi Title		guifg=#dfeff6 guibg=NONE	gui=bold
+ " Selected text color
+hi Visual		guifg=#dfeff6 guibg=#24557A gui=none
+hi SpecialKey	guifg=#3e71a1 guibg=#102235 gui=none
+
+"
+" Syntax highlighting
+"
+hi Comment 		guifg=#3e71a1 gui=italic
+hi Todo 		guifg=#ADED80 guibg=#579929 gui=bold
+hi Constant 	guifg=#96defa gui=none
+hi String 		guifg=#89e14b gui=italic
+ " names of variables in PHP
+hi Identifier 	guifg=#8ac6f2 gui=none
+ " Function names as in python. currently purleish
+hi Function 	guifg=#AF81F4 gui=none
+ " declarations of type, e.g. int blah
+hi Type 		guifg=#41B2EA gui=none
+ " statement, such as 'hi' right here
+hi Statement 	guifg=#68CEE8 gui=none
+hi Keyword		guifg=#8ac6f2 gui=none
+ "  specified preprocessed words (like bold, italic etc. above)
+hi PreProc 		guifg=#EF6145 gui=none
+hi Number		guifg=#96defa gui=none
+hi Special		guifg=#3e71a1 gui=none
+
+