Move "make install" to the build phase instead of the test phase

[rsdunlapiv]

The argument for this is that the make install command can reveal linking problems that are more closely associated with the build than running the test suite.

[theurich]

Having "make install" as part of build does make sense. Another way to test linking issues during build would be to add the "make build_apps" target. I am not sure we are testing this target explicitly anywhere right now. It is indirectly tested during "make install", so that does cover it.
I guess an option would be to add "make build_apps" to the build phase, and keep "make install" part of the test phase. Both targets would identify linking issues.