Cap installed pip to be < 8

Pip 8 just release which made uninstalling distutils installed packages
fatal. This was previously a deprecation warning and is now causing all
dsvm jobs to fail.

Depends-On: I511d216d9d8619c7cf919c482aaead4e833cdaac
Change-Id: I22f5c3af1adf96cfbd5747122f915a82e947843a
diff --git a/tools/cap-pip.txt b/tools/cap-pip.txt
new file mode 100644
index 0000000..1a6f80c
--- /dev/null
+++ b/tools/cap-pip.txt
@@ -0,0 +1 @@
+pip<8
diff --git a/tools/install_pip.sh b/tools/install_pip.sh
index f239c7b..542a284 100755
--- a/tools/install_pip.sh
+++ b/tools/install_pip.sh
@@ -77,9 +77,9 @@
             die $LINENO "Download of get-pip.py failed"
         touch $LOCAL_PIP.downloaded
     fi
-    sudo -H -E python $LOCAL_PIP
+    sudo -H -E python $LOCAL_PIP -c $TOOLS_DIR/cap-pip.txt
     if python3_enabled; then
-        sudo -H -E python${PYTHON3_VERSION} $LOCAL_PIP
+        sudo -H -E python${PYTHON3_VERSION} $LOCAL_PIP -c $TOOLS_DIR/cap-pip.txt
     fi
 }