Fixed JSON

This closes #40.

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Note that this is not a list of calls but a call legs

See issue #43

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Empty params request returns current params

Closes #42.

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>