sdp.py: sync with recent changes to cvxpy api
.gitignore: also exclude .pyc files

Signed-off-by: Jacob <jre2718@berkeley.edu>
sdp.py: switch to using tempfile for temporary files
add sdp_main.py to test single spectrahedra

Signed-off-by: Jacob <jre2718@berkeley.edu>
set scripts to be executable

Signed-off-by: Jacob <jre2718@berkeley.edu>