Migrate to use v0.14 API

[cosmo0920]

I've tried to use v0.14 Output Plugin API.
I've tested with the following config(without sensitive information):

<source>
    @type tail                         # input plugin
    path /var/log/apache2/access.log   # monitoring file
    pos_file /tmp/fluentd_pos_file     # position file
    format apache                      # format
    tag azure-loganalytics.access      # tag
</source>

<match azure-loganalytics.**>
    @type azure-loganalytics
    customer_id MY_CUSTOMER_KEY
    shared_key MY_SHARED_KEY
    log_type ApacheAccessLog
</match>

Thanks,

[yokawasa]

@cosmo0920
I confirmed that everything works well with Fluentd v0.14. Thanks alot!