Instead, either use the bash built-in of type to ensure it exists. Since
which is an external dep, things can fail oddly in a constrained
environment.
Also add a dib-lint test for this.
Change-Id: I645029f5b5bfe1198c89ce10fd3246be8636e8af
Signed-off-by: Jesse Keating <omgjlk@us.ibm.com>