Mac安装cocoapods

安装过程：

Last login: Tue Mar 26 13:05:49 on ttys003
seenochengdeMacBook-Pro:~ see$ rvm -v
-bash: rvm: command not found
seenochengdeMacBook-Pro:~ see$ curl -L get.rvm.io | bash -s stable
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   194  100   194    0     0    217      0 --:--:-- --:--:-- --:--:--   217
100 24173  100 24173    0     0   8677      0  0:00:02  0:00:02 --:--:-- 14202
Downloading https://github.com/rvm/rvm/archive/1.29.7.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.7/1.29.7.tar.gz.asc
Found PGP signature at: 'https://github.com/rvm/rvm/releases/download/1.29.7/1.29.7.tar.gz.asc',
but no GPG software exists to validate it, skipping.
Installing RVM to /Users/see/.rvm/
    Adding rvm PATH line to /Users/see/.profile /Users/see/.mkshrc /Users/see/.bashrc /Users/see/.zshrc.
    Adding rvm loading line to /Users/see/.profile /Users/see/.bash_profile /Users/see/.zlogin.
Installation of RVM in /Users/see/.rvm/ is almost complete:

  * To start using RVM you need to run `source /Users/see/.rvm/scripts/rvm`
    in all your open shell windows, in rare cases you need to reopen all shell windows.
seenochengdeMacBook-Pro:~ see$ source /Users/see/.rvm/scripts/rvm
seenochengdeMacBook-Pro:~ see$ rvm -v
rvm 1.29.7 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
seenochengdeMacBook-Pro:~ see$ rvm list known
# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10]
[ruby-]2.2[.10]
[ruby-]2.3[.8]
[ruby-]2.4[.5]
[ruby-]2.5[.3]
[ruby-]2.6[.0]
ruby-head

# for forks use: rvm install ruby-head-<name> --url https://github.com/github/ruby.git --branch 2.2

# JRuby
jruby-1.6[.8]
jruby-1.7[.27]
jruby-9.1[.17.0]
jruby[-9.2.5.0]
jruby-head

# Rubinius
rbx-1[.4.3]
rbx-2.3[.0]
rbx-2.4[.1]
rbx-2[.5.8]
rbx-3[.100]
rbx-head

# TruffleRuby
truffleruby[-1.0.0-rc10]

# Opal
opal

# Minimalistic ruby implementation - ISO 30170:2012
mruby-1.0.0
mruby-1.1.0
mruby-1.2.0
mruby-1.3.0
mruby-1[.4.1]
mruby-2[.0.0]
mruby[-head]

# Ruby Enterprise Edition
ree-1.8.6
ree[-1.8.7][-2012.02]

# Topaz
topa