fixes bug related with using CONTAINER_URI and STATIC_CONTAINER
added syncmedia management command
Mention new required parameter in "Usage" section

`PYRAX_IDENTITY_TYPE` is a required parameter, it must be in the
documentation early on. (#144)
Merge pull request #148 from baffolobill/master

fixes bug related with using CONTAINER_URI and STATIC_CONTAINER
Merge branch 'master' into syncstatic-headers