pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.

Could not fetch URL https:*******: There was a problem confirming the ssl certificate: 
Can't connect to HTTPS URL because the SSL module is not available. - skipping

本人查阅资料发现，在./configure过程中，如果没有加上–with-ssl参数时，默认安装的软件涉及到ssl的功能不可用，
刚好pip3过程需要ssl模块，而由于没有指定，所以该功能不可用。

1. 查看openssl安装包，发现缺少openssl-devel包 
   [root@localhost ~]# rpm -aq|grep openssl 
   openssl-0.9.8e-20.el5 
   openssl-0.9.8e-20.el5 
   [root@localhost ~]#

2. yum安装openssl-devel 
   [root@localhost ~]# yum install openssl-devel -y 
   查看安装结果 
   [root@localhost ~]# rpm -aq|grep openssl 
   openssl-0.9.8e-26.el5_9.1 
   openssl-0.9.8e-26.el5_9.1 
   openssl-devel-0.9.8e-26.el5_9.1 
   openssl-devel-0.9.8e-26.el5_9.1

3. 重新对python3.6进行编译安装，用一下过程来实现编译安装:

cd Python-3.6.4
./configure --with-ssl
make
sudo make install