fixed write SSLCERTHOST file (#149)
fixed write SSLCERTHOST file (#149)

* Update Dockerfile

bump ejabberd version to 17.08 for XEP-0357 Push Notifications

* bump version in readme

* install cacert certificate into keystore for s2s verification

* bump to version 17.08

* fixed write SSLCERTHOST file

sulphur/docker-ejabberd,rroemhild/docker-ejabberd