integcli: speed up TestBuildSixtySteps

This improves the TestBuildSixtySteps test by switching from busybox to
scratch and simply adding a file.

This lowers the execution time of that test from 20 seconds to 5
seconds.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)

integration-cli/build_tests/TestBuildSixtySteps/Dockerfile

@@ -1,60 +1,60 @@
-FROM busybox
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
-RUN echo "foo"
+FROM scratch
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /
+ADD foo /

integration-cli/build_tests/TestBuildSixtySteps/foo

@@ -0,0 +1 @@
+a