Install test-requirements with main install

To reduce the total number of invocations necessary for pip which isn't
the quickest thing ever (due to needing to evaluate constraints and deps
lists and what is currently installed) combine the main installation of
software with its test-requirements.txt file which should roughly halve
our pip invocations.

Change-Id: Ibcc3264136e66d34a879ad1c90a62e1bb6a84243

inc/python

@@ -320,6 +320,14 @@ function pip_install {
     fi
 
     $xtrace
+
+    # Also install test requirements
+    local install_test_reqs=""
+    local test_req="${!#}/test-requirements.txt"
+    if [[ -e "$test_req" ]]; then
+        install_test_reqs="-r $test_req"
+    fi
+
     # adding SETUPTOOLS_SYS_PATH_TECHNIQUE is a workaround to keep
     # the same behaviour of setuptools before version 25.0.0.
     # related issue: https://github.com/pypa/pip/issues/3874
@@ -329,24 +337,10 @@ function pip_install {
         no_proxy="${no_proxy:-}" \
         PIP_FIND_LINKS=$PIP_FIND_LINKS \
         SETUPTOOLS_SYS_PATH_TECHNIQUE=rewrite \
-        $cmd_pip $upgrade \
+        $cmd_pip $upgrade $install_test_reqs \
         $@
     result=$?
 
-    # Also install test requirements
-    local test_req="${!#}/test-requirements.txt"
-    if [[ $result == 0 ]] && [[ -e "$test_req" ]]; then
-        echo "Installing test-requirements for $test_req"
-        $sudo_pip \
-            http_proxy=${http_proxy:-} \
-            https_proxy=${https_proxy:-} \
-            no_proxy=${no_proxy:-} \
-            PIP_FIND_LINKS=$PIP_FIND_LINKS \
-            $cmd_pip $upgrade \
-            -r $test_req
-        result=$?
-    fi
-
     time_stop "pip_install"
     return $result
 }