Add health check

autoload/SpaceVim/health.vim

@@ -0,0 +1,18 @@
+function! SpaceVim#health#report() abort
+    let items = map(SpaceVim#util#globpath(&rtp,'autoload/SpaceVim/health/*'), "fnamemodify(v:val,':t:r')")
+    let report = []
+    for item in items
+        try
+            let result = SpaceVim#health#{item}#check()
+            call extend(report,result)
+        catch /^Vim\%((\a\+)\)\=:E117/
+            call extend(report,[
+                        \ '',
+                        \ 'SpaceVim Health Error:',
+                        \ '    There is no function: SpaceVim#health#' . item . '#check()',
+                        \ '',
+                        \ ])
+        endtry
+    endfor
+    return join(report, "\n")
+endfunction