centos下安装证书

centos下要跑个https的 request，需要安装证书，否则代码上要多写许多

Add

1. Install the ca-certificates package:

   yum install ca-certificates

2. Enable the dynamic CA configuration feature:

   update-ca-trust force-enable

3. Add it as a new file to /etc/pki/ca-trust/source/anchors/:

   cp foo.crt /etc/pki/ca-trust/source/anchors/

4. Use command:

   update-ca-trust extract