correctly set permissions when writing configuration files

This will ensure that every user can read the configuration file when it is being written.

It also bumps the version for the requirement of  `remoto` to 0.0.14 that uses the latest execnet.

Before:

    ceph-deploy admin node1 && ssh node1 ls -alh /etc/ceph
    [ceph_deploy.cli][INFO  ] Invoked (1.3.4): /Users/alfredo/.virtualenvs/ceph-deploy/bin/ceph-deploy admin node1
    [ceph_deploy.admin][DEBUG ] Pushing admin keys and conf to node1
    [node1][DEBUG ] connected to host: node1
    [node1][DEBUG ] detect platform information from remote host
    [node1][DEBUG ] detect machine type
    [node1][DEBUG ] get remote short hostname
    [node1][DEBUG ] write cluster configuration to /etc/ceph/{cluster}.conf
    total 20K
    drwxr-xr-x  2 root root 4.0K Jan 29 18:57 .
    drwxr-xr-x 81 root root 4.0K Jan 22 18:39 ..
    -rw-r--r--  1 root root   64 Jan 29 18:57 ceph.client.admin.keyring
    -rw-------  1 root root  188 Jan 29 18:57 ceph.conf
    -rw-r--r--  1 root root   92 Dec 20 22:01 rbdmap

After:

    ceph-deploy admin node1 && ssh node1 ls -alh /etc/ceph
    [ceph_deploy.cli][INFO  ] Invoked (1.3.4): /Users/alfredo/.virtualenvs/ceph-deploy/bin/ceph-deploy admin node1
    [ceph_deploy.admin][DEBUG ] Pushing admin keys and conf to node1
    [node1][DEBUG ] connected to host: node1
    [node1][DEBUG ] detect platform information from remote host
    [node1][DEBUG ] detect machine type
    [node1][DEBUG ] get remote short hostname
    [node1][DEBUG ] write cluster configuration to /etc/ceph/{cluster}.conf
    total 20K
    drwxr-xr-x  2 root root 4.0K Jan 29 18:58 .
    drwxr-xr-x 81 root root 4.0K Jan 22 18:39 ..
    -rw-r--r--  1 root root   64 Jan 29 18:58 ceph.client.admin.keyring
    -rw-r--r--  1 root root  188 Jan 29 18:58 ceph.conf
    -rw-r--r--  1 root root   92 Dec 20 22:01 rbdmap