Remove spaces after C in demoCourse.list

should get rid of the error messages about 'C ' not being recognized.
Merge branch 'release/1.7' of https://github.com/openwebwork/webwork2 into release/2.7
Merge branch 'release/2.7' of https://github.com/openwebwork/webwork2 into release/2.7
Fix typo in Cosign.pm for Gavin
Merge pull request #73 from mgage/release/2.7

Fix typo in Cosign.pm