Change IDAES installation back to main

[dallan-keylogic]

#150 changed the IDAES source to #1667. Once #1667 is merged, we need to change it back to idaes-pse main.

[dallan-keylogic]

As of #157, we are installing from a branch, which needs to be reverted after IDAES/idaes-pse#1704 is merged