CLC-3967 Add site memberships maintainer to handle both incremental & batch mode
CLC-4030 Add instructor to new course site via API rather than SIS import
Also removes unnecessary restriction on section ID formats.
CLC-3967 Simplify API to use more flexible enrollments proxy
CLC-3967 Import enrollments in course provisioning
NOJIRA Fix typo in variable name
Merge pull request #2781 from raydavis/enr

CLC-3967 CLC-4030 Import enrollments in course provisioning; safely add instructor as teacher