Update infra_paths to use START_DIR

CURRENT_WORKING_DIR in path module was renamed to START_DIR. Update
infra_paths accordingly.

This includes recipe_engine roll.

R=iannucci@chromium.org, martiniss@chromium.org
BUG=662586

Change-Id: I913c16b1a185c5b753284ed934a5e60912887f0f
Reviewed-on: https://chromium-review.googlesource.com/412055
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>

infra/config/recipes.cfg

@@ -5,5 +5,5 @@ deps {
   project_id: "recipe_engine"
   url: "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
   branch: "master"
-  revision: "672570bf06c6b438b353a4c42d4d38ceab089eea"
+  revision: "ae33ef8b45421475037af149dc9dadd8bcf03920"
 }

recipe_modules/infra_paths/path_config.py

@@ -13,8 +13,8 @@ def infra_common(c):
 
 @CONFIG_CTX(includes=['infra_common'])
 def infra_buildbot(c):
-  c.base_paths['root'] = c.CURRENT_WORKING_DIR[:-4]
+  c.base_paths['root'] = c.START_DIR[:-4]
-  c.base_paths['slave_build'] = c.CURRENT_WORKING_DIR
+  c.base_paths['slave_build'] = c.START_DIR
   c.base_paths['cache'] = c.base_paths['root'] + (
       'build', 'slave', 'cache')
   c.base_paths['git_cache'] = c.base_paths['root'] + (
@@ -27,11 +27,11 @@ def infra_buildbot(c):
 
 @CONFIG_CTX(includes=['infra_common'])
 def infra_kitchen(c):
-  c.base_paths['root'] = c.CURRENT_WORKING_DIR
+  c.base_paths['root'] = c.START_DIR
-  c.base_paths['slave_build'] = c.CURRENT_WORKING_DIR
+  c.base_paths['slave_build'] = c.START_DIR
   # TODO(phajdan.jr): have one cache dir, let clients append suffixes.
 
-  b_dir = c.CURRENT_WORKING_DIR
+  b_dir = c.START_DIR
   while b_dir and b_dir[-1] != 'b':
     b_dir = b_dir[:-1]
 
@@ -55,4 +55,4 @@ def infra_kitchen(c):
 
 @CONFIG_CTX(includes=['infra_buildbot'])
 def infra_swarmbucket(c):
-  c.base_paths['git_cache'] = c.CURRENT_WORKING_DIR + ('git_cache',)
+  c.base_paths['git_cache'] = c.START_DIR + ('git_cache',)