Autocomplete in soy files

gistfile1.json

{
        "keys": [
            "tab"
        ], 
        "command": "expand_abbreviation_by_tab", 
        "context": [
            {
                "operand": "source.css, source.sass, source.less, source.scss, source.stylus, source.jade, text.slim, text.xml, text.html - source, text.haml, text.scala.html, source string, source.soy", 
                "operator": "equal", 
                "match_all": true, 
                "key": "selector"
            }, 
            {
                "operand": "storage.type.templatetag.django", 
                "operator": "not_equal", 
                "match_all": true, 
                "key": "selector"
            }, 
            {
                "match_all": true, 
                "key": "selection_empty"
            }, 
            {
                "operator": "equal", 
                "operand": false, 
                "match_all": true, 
                "key": "has_next_field"
            }, 
            {
                "operator": "equal", 
                "operand": false, 
                "match_all": true, 
                "key": "setting.disable_tab_abbreviations"
            }, 
            {
                "operand": false, 
                "operator": "equal", 
                "match_all": true, 
                "key": "auto_complete_visible"
            }, 
            {
                "match_all": true, 
                "key": "is_abbreviation"
            }
        ]
    }