Convert the attributes to jaeger tags.

def _convert_attribute_to_tag(key, attr):
    """Convert the attributes to jaeger tags."""
    if isinstance(attr, bool):
        return jaeger.Tag(
            key=key,
            vBool=attr,
            vType=jaeger.TagType.BOOL)
    if isinstance(attr, str):
        return jaeger.Tag(
            key=key,
            vStr=attr,
            vType=jaeger.TagType.STRING)
    if isinstance(attr, int):
        return jaeger.Tag(
            key=key,
            vLong=attr,
            vType=jaeger.TagType.LONG)
    if isinstance(attr, float):
        return jaeger.Tag(
            key=key,
            vDouble=attr,
            vType=jaeger.TagType.DOUBLE)
    logging.warn('Could not serialize attribute \
            {}:{} to tag'.format(key, attr))
    return None