Composer does not install Calendar Module
Is the module installing and working locally? I've had a similar issue with dev modules before. The problem is that they will ship with a .git directory and sometimes when I try to commit the module to my project's git repo it won't be committed because of the .git in the submodule. I bet if you navigate to the calendar directory on your server it will be empty.

A solution to this is to remove the .git directory from the submodule, e.g. /modules/contrib/calendar/.git before committing to your project's repo. If you've already committed, git will probably still try to ignore the directory after you remove the .git from the submodule, but you can remedy this by using git rm -r --cached modules/contrib/calendar (or whatever appropriate path). Then you can git add and git commit the submodule.