Use explicit version for TCL interpreter

Summary:
This fix the following issue:

$ make
cd tests && tclsh all.tcl
/bin/sh: tclsh: not found
*** Error code 127

Stop.
make: stopped in /usr/home/dereckson/dev/nasqueron/viperserv/viperserv

Test Plan: make test

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D1204