Add variables for change running tests

Related-prod: PRODX-3417
Change-Id: Ia72e147518fa549587273a500ae15861b4da0a64
diff --git a/Dockerfile b/Dockerfile
index 22e7e3e..b044a9c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,7 +20,7 @@
     git \
     x11-xkb-utils
 
-ENV DISPLAY=1
+ENV SELENIUM_HEADLESS=1
 
 RUN wget https://artifactory.mcp.mirantis.net/artifactory/binary-dev-local/tarballs/geckodriver-v0.24.0-linux64.tar.gz
 RUN tar xvzf geckodriver-v0.24.0-linux64.tar.gz && \
@@ -29,5 +29,5 @@
 
 WORKDIR /opt/horizon
 
-RUN pip3 install tox -U -r requirements.txt -r test-requirements.txt
+RUN pip3 install -r requirements.txt -r test-requirements.txt -c requirements/upper-constraints.txt