Add acceptedStudentsCSVExport function to stats.py script. This funtion is used to generate CSV with all accepted students. It still needs some work and I left TODOs there. I also added helper function for saving data to CSV, which can be reused for other kinds of reports.

# use glob syntax.
syntax: glob

*.pyc
*.zip
*~
.project
.pydevproject
app.yaml
build
tests/coverageResults
*,cover
tests/.coverage
*.git
.gitignore
.DS_Store