JSON will no longer be supported or out-of-date

[iWeslie]

As I run bundle install, it broke down and reported an error.

An error occurred while installing json (1.8.3), and Bundler cannot continue.
Make sure that `gem install json -v '1.8.3'` succeeds before bundling.

After serious ways I tried. Finally I found the solution.

$ brew update json    
$ brew install    

Then bundle install will work without error. But I have finally failed because there are too much problems while installing dependencies.
run bundle exec pod install will output the error

[!] Unable to find a specification for 'Artsy+OSSUIFonts'.

I haven't found any ways to eliminate the error. HELP!!