Provider Configurations TODOs

[shriharshs]

1. Make provider configurations file name conventional.
2. Placing the configurations file in right location (currently placed inside "bin/sms-provider")
3. Adding active sms provider attribute to the credentials file, to pick the right sms-provider dynamically.
4. Remove sms_base_url from configurations.
5. Remove sms_get_url from configurations.
6. Remove sms_post_url from configurations.