docs: add images for lecture 18

3b8395bb · George Adrian Stoica · 39d07d98 · 3b8395bb · 3b8395bb · 3b8395bb
Commit 3b8395bb authored Nov 08, 2021 by George Adrian Stoica
--- a/lectures/revealjs/images/lecture18/integration-tests.png
+++ b/lectures/revealjs/images/lecture18/integration-tests.png
--- a/lectures/revealjs/images/lecture18/mocked-client.png
+++ b/lectures/revealjs/images/lecture18/mocked-client.png
--- a/lectures/revealjs/images/lecture18/mocked-server.png
+++ b/lectures/revealjs/images/lecture18/mocked-server.png
--- a/lectures/revealjs/images/lecture18/system-units.png
+++ b/lectures/revealjs/images/lecture18/system-units.png
--- a/lectures/revealjs/images/lecture18/test-pyramid.png
+++ b/lectures/revealjs/images/lecture18/test-pyramid.png
--- a/lectures/revealjs/images/lecture18/unit-tests.png
+++ b/lectures/revealjs/images/lecture18/unit-tests.png