tools: add python future module

requirements.txt

@@ -3,6 +3,7 @@ bcrypt==3.1.5
 cffi==1.11.5
 cryptography==2.4.2
 fabric==2.4.0
+future==0.17.1
 idna==2.8
 invoke==1.2.0
 paramiko==2.4.2

tools/BUILD

@@ -6,6 +6,9 @@ py_binary(
     name = "secretstore",
     srcs = ["secretstore.py"],
     visibility = ["//visibility:public"],
+    deps = [
+        requirement("future"),
+    ],
 )
 
 py_binary(
@@ -14,6 +17,7 @@ py_binary(
     visibility = ["//visibility:public"],
     deps = [
         requirement("fabric"),
+        requirement("future"),
     ],
 )