Added -k option to curl command
Added -k to disable certificate check when downloading with curl
Revert "Added configurable netrc path"

This reverts commit 3a90b1ce8ec9be9a716642294677953fcd8583c6.

Conflicts:

	coursera/coursera_dl.py
Merge branch 'master' of https://github.com/sdbakker/coursera

Conflicts:
	coursera/coursera_dl.py