Fix ReadMe to reflect required Boost version.

A small tweak to cause a rebuild.
11 jobs for exodus-uuid-export
latest
Status Job ID Name Coverage
  External
passed cdash

passed kwrobot-branch-check

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

00:07:16

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

failed smtk-endor-linux-shared-relwithdebinfo

00:00:17