Add tasks to projects that do not affect the project duration

[#1]

When brand submits a request, and asks for a certain deadline, there are often times when we can get 90% of what they want done by the due date, but we have some long-term tests that often go beyond the due date (and Brand is okay with this). however, those long running tests/tasks push the planned completion date way out.. so we’re trying to figure out how to have the planned completion date be the due date requested by brand, but still be able to track these long-running tests.