crit: run unit tests with coverage results

There are two ways we can enable test coverage for the unit tests:
1) `-coverprofile` and 2) `-cover`. The first method stores the results
in a file that we can upload with `codecov`. The second method only
outputs the test coverage results to standard output.

This patch set the default value of GOFLAGS to `-cover` to
always show the coverage of unit tests.

Suggested-by: Adrian Reber <[email protected]>
Signed-off-by: Radostin Stoyanov <[email protected]>

crit/Makefile

@@ -51,6 +51,7 @@ test-imgs: ../test/loop/loop
 	pkill -9 loop
 
 unit-test: test-imgs
+	$(eval GOFLAGS ?= -cover)
 	go test ${GOFLAGS} -v ./...
 
 clean: