Update mrstub with nginx

Support http/https for mrstub
http port 3905
https port 3906
Add timeout for mr AGENT_READ_URL

Issue-ID: NONRTRIC-208
Change-Id: I222906b705f273b2e582ad8ce80fa88b2e582824
Signed-off-by: Chengkai Yan <martin.c.yan@est.tech>
diff --git a/test/mrstub/app/requirements.txt b/test/mrstub/app/requirements.txt
new file mode 100644
index 0000000..8fd414f
--- /dev/null
+++ b/test/mrstub/app/requirements.txt
@@ -0,0 +1,2 @@
+pip==20.1
+Flask==1.1.2
\ No newline at end of file