Conform to the new 1.1.0 openPMD standard

Branch: berkeleylab/atap-warp:openPMD-1.1

Branch: berkeleylab/warp:master

Merged

#164 · Created 2018-02-06 · Last updated 2018-02-07

Merged pull request

Merged in berkeleylab/atap-warp/openPMD-1.1 (pull request #164)

9c91a0a·Author: Remi Lehe·Closed by: Remi Lehe·2018-02-07

In openPMD 1.1.0, the meshesPath and particlesPath are optional (indicating that there are no fields/particles, if these attributes are not set).

This pull requests updates the openPMD writer, so as to conform to these changes.