[add] vim-themis's test

test/.themisrc

@@ -0,0 +1,2 @@
+let s:deps = themis#helper('deps')
+call s:deps.git('vim-airline/vim-airline')

test/airline-themes.vim

@@ -0,0 +1,18 @@
+scriptencoding utf-8
+
+let s:themes_dir = expand('<sfile>:h:h') . '/autoload/airline/themes'
+let s:themes = map(glob(s:themes_dir . '/*.vim', 1, 1), 'fnamemodify(v:val, ":t:r")')
+let s:suite = themis#suite('vim-airline-themes')
+
+call themis#helper('command')
+
+function! s:Test(theme)
+  Throws execute('AirlineTheme ' . a:theme)
+endfunction
+
+function! s:suite.__themes__()
+  let child = themis#suite('ExistThemes')
+  for theme in s:themes
+    let child[theme] = funcref('s:Test', [theme])
+  endfor
+endfunction