Description of problem:

  Credentials for connection to calamari are hardcoded in the code[1], which makes problem during importing existing cluster and also might be security vulnerability.

Version-Release number of selected component (if applicable):
  ceph-ansible-1.0.5-19.el7scon.noarch
  ceph-deploy-1.5.33-0.noarch
  ceph-installer-1.0.11-1.el7scon.noarch
  rhscon-ceph-0.0.20-1.el7scon.x86_64
  rhscon-core-0.0.21-1.el7scon.x86_64
  rhscon-ui-0.0.34-1.el7scon.noarch
  
  calamari-server-1.4.0-0.12.rc15.el7cp.x86_64
  ceph-10.2.1-11.el7cp.x86_64
  ceph-base-10.2.1-11.el7cp.x86_64
  ceph-common-10.2.1-11.el7cp.x86_64
  ceph-mds-10.2.1-11.el7cp.x86_64
  ceph-mon-10.2.1-11.el7cp.x86_64
  ceph-osd-10.2.1-11.el7cp.x86_64
  ceph-selinux-10.2.1-11.el7cp.x86_64
  rhscon-agent-0.0.9-1.el7scon.noarch

How reproducible:
  100%

Steps to Reproduce:
1. Try to create new one or import existing cluster to USM, there is no way to configure calamari credentials.
2. Check source code[1] and look for lines
    reqData["username"] = "admin"
    reqData["password"] = "admin"

Actual results:
  Calamari credentials are hardcoded to admin/admin, so it is not possible to change them for security reason and also it is not possible to import existing cluster with different credentials for accessing calamari.

Expected results:
  It should be possible to change calamari credentials in skyring, so it is possible to secure calamari with good password and also it should be possible to import existing cluster with various credentials to calamari.

Additional info:
  [1] https://github.com/skyrings/bigfin/blob/master/backend/cephapi/handler/handler.go#L188