Remove -U from pip install

'pip install -U' ugrades specified packages, this is not necessary
since we use constraints, remove the parameter '-U' from the line.

With tools/tox_install.sh - which a previous change of mine removed -
the -U was not harmful, but with the current set up, it might cause
upgrades, so remove it.

Change-Id: Ib240b8c16dce80910d952e9eec860669af1ec399
(cherry picked from commit 47031b6087b25e6cb346563d8280fdbe7ff36c99)

1 files changed, 1 insertions, 1 deletions

diff --git a/tox.ini b/tox.ini
index 0fbe3e9..1691ff3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+install_command = pip install {opts} {packages}
 setenv =
     VIRTUAL_ENV={envdir}
     DISCOVER_DIRECTORY=saharaclient/tests/unit