Add monitor web page to Health Check test

Also add documentation.

Change-Id: I4732a65d21a458711672f6f49d56d186b15bd8c8
Issue-ID: NONRTRIC-200
Signed-off-by: elinuxhenrik <henrik.b.andersson@est.tech>
diff --git a/test/usecases/healthcheck/src/requirements.txt b/test/usecases/healthcheck/src/requirements.txt
new file mode 100644
index 0000000..7018123
--- /dev/null
+++ b/test/usecases/healthcheck/src/requirements.txt
@@ -0,0 +1,3 @@
+Flask==1.1.1
+jinja2==2.11.2
+pygments==2.2.0