Add release-techo make target to the makefile

[jeremybox]

The t-echo does not have a release build in the Makefile

-add release-techo section,
-also add release-techo to the release-all section.

should be a quick change but I don't have the moment to do this right now and want to track it so I don't forget, or to allow someone else to do it if I get distracted and wander off.

[jacobeva]

Will be closed once @jeremybox verifies commit 0f63ae4 fixes this.