Create EDXAPP_GIT_REPO_EXPORT_DIR directory
Create EDXAPP_GIT_REPO_EXPORT_DIR directory

The edxapp role defines both EDXAPP_GIT_REPO_DIR (the directory
where courses being imported from a Git repo are staged) and
EDXAPP_GIT_REPO_EXPORT_DIR (the reverse, for export to a Git repo).

It also populates the LMS/CMS variables GIT_REPO_DIR and
GIT_REPO_EXPORT_DIR, but only creates the directory for the former.

Fix the edxapp role so that it creates both directories.

edx/configuration,stvstnfrd/configuration,EDUlib/configuration,mitodl/configuration,edx/configuration,EDUlib/configuration,EDUlib/configuration,EDUlib/configuration,arbrandes/edx-configuration,arbrandes/edx-configuration,mitodl/configuration,arbrandes/edx-configuration,mitodl/configuration,stvstnfrd/configuration,EDUlib/configuration,arbrandes/edx-configuration,stvstnfrd/configuration,mitodl/configuration,arbrandes/edx-configuration,stvstnfrd/configuration,edx/configuration,stvstnfrd/configuration,edx/configuration