升级Rubygems的ruby版本

Question

我在尝试安装rhc程序时收到错误：

~$ sudo gem install rhc
    ERROR:  Error installing rhc:
        net-ssh requires Ruby version >= 2.0.

~/.gem/ruby$ ls
1.8

~$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 2.6.10
  - RUBY VERSION: 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux]
  - INSTALLATION DIRECTORY: /var/lib/gems/1.8
  - USER INSTALLATION DIRECTORY: /home/mypc/.gem/ruby/1.8
  - RUBY EXECUTABLE: /usr/bin/ruby1.8
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - SPEC CACHE DIRECTORY: /home/mypc/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /etc
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /var/lib/gems/1.8
     - /home/mypc/.gem/ruby/1.8
     - /usr/lib/x86_64-linux/rubygems-integration/1.8
     - /usr/share/rubygems-integration/1.8
     - /usr/share/rubygems-integration/all

~$ ruby -v
    ruby 2.3.1p112 (2016-04-26) [x86_64-linux-gnu]

~$ sudo gem install net-ssh -v 2.9.2
   Fetching: net-ssh-2.9.2.gem (100%)
   Successfully installed net-ssh-2.9.2
   1 gem installed
   Installing ri documentation for net-ssh-2.9.2...
   Installing RDoc documentation for net-ssh-2.9.2... 

~$ sudo gem install rhc
ERROR:  Error installing rhc:
    net-ssh requires Ruby version >= 2.0.

请知道我该如何解决。谢谢。