Update vendored skylib to 0.5.0 (#1831)

Related #1829

go/private/skylib/README.rst

@@ -1,5 +1,5 @@
 This directory is a copy of github.com/bazelbuild/bazel-skylib/lib.
-Version 0.4.0, retrieved on 2018-06-11
+Version 0.5.0, retrieved on 2018-11-26.
 
 This is needed only until nested workspaces works.
 It has to be copied in because we use the functionality inside code that 

go/private/skylib/lib/collections.bzl

@@ -14,60 +14,56 @@
 
 """Skylib module containing functions that operate on collections."""
 
-
 def _after_each(separator, iterable):
-  """Inserts `separator` after each item in `iterable`.
-
-  Args:
-    separator: The value to insert after each item in `iterable`.
-    iterable: The list into which to intersperse the separator.
+    """Inserts `separator` after each item in `iterable`.
 
-  Returns:
-    A new list with `separator` after each item in `iterable`.
-  """
-  result = []
-  for x in iterable:
-    result.append(x)
-    result.append(separator)
+    Args:
+      separator: The value to insert after each item in `iterable`.
+      iterable: The list into which to intersperse the separator.
 
-  return result
+    Returns:
+      A new list with `separator` after each item in `iterable`.
+    """
+    result = []
+    for x in iterable:
+        result.append(x)
+        result.append(separator)
 
+    return result
 
 def _before_each(separator, iterable):
-  """Inserts `separator` before each item in `iterable`.
+    """Inserts `separator` before each item in `iterable`.
 
-  Args:
-    separator: The value to insert before each item in `iterable`.
-    iterable: The list into which to intersperse the separator.
+    Args:
+      separator: The value to insert before each item in `iterable`.
+      iterable: The list into which to intersperse the separator.
 
-  Returns:
-    A new list with `separator` before each item in `iterable`.
-  """
-  result = []
-  for x in iterable:
-    result.append(separator)
-    result.append(x)
-
-  return result
+    Returns:
+      A new list with `separator` before each item in `iterable`.
+    """
+    result = []
+    for x in iterable:
+        result.append(separator)
+        result.append(x)
 
+    return result
 
 def _uniq(iterable):
-  """Returns a list of unique elements in `iterable`.
-
-  Requires all the elements to be hashable.
+    """Returns a list of unique elements in `iterable`.
 
-  Args:
-    iterable: An iterable to filter.
+    Requires all the elements to be hashable.
 
-  Returns:
-    A new list with all unique elements from `iterable`.
-  """
-  unique_elements = {element: None for element in iterable}
-  return unique_elements.keys()
+    Args:
+      iterable: An iterable to filter.
 
+    Returns:
+      A new list with all unique elements from `iterable`.
+    """
+    unique_elements = {element: None for element in iterable}
+    return unique_elements.keys()
 
 collections = struct(
-    after_each=_after_each,
-    before_each=_before_each,
-    uniq=_uniq,
+    after_each = _after_each,
+    before_each = _before_each,
+    uniq = _uniq,
 )

go/private/skylib/lib/dicts.bzl

@@ -14,30 +14,28 @@
 
 """Skylib module containing functions that operate on dictionaries."""
 
-
 def _add(*dictionaries):
-  """Returns a new `dict` that has all the entries of the given dictionaries.
-
-  If the same key is present in more than one of the input dictionaries, the
-  last of them in the argument list overrides any earlier ones.
+    """Returns a new `dict` that has all the entries of the given dictionaries.
 
-  This function is designed to take zero or one arguments as well as multiple
-  dictionaries, so that it follows arithmetic identities and callers can avoid
-  special cases for their inputs: the sum of zero dictionaries is the empty
-  dictionary, and the sum of a single dictionary is a copy of itself.
+    If the same key is present in more than one of the input dictionaries, the
+    last of them in the argument list overrides any earlier ones.
 
-  Args:
-    *dictionaries: Zero or more dictionaries to be added.
+    This function is designed to take zero or one arguments as well as multiple
+    dictionaries, so that it follows arithmetic identities and callers can avoid
+    special cases for their inputs: the sum of zero dictionaries is the empty
+    dictionary, and the sum of a single dictionary is a copy of itself.
 
-  Returns:
-    A new `dict` that has all the entries of the given dictionaries.
-  """
-  result = {}
-  for d in dictionaries:
-    result.update(d)
-  return result
+    Args:
+      *dictionaries: Zero or more dictionaries to be added.
 
+    Returns:
+      A new `dict` that has all the entries of the given dictionaries.
+    """
+    result = {}
+    for d in dictionaries:
+        result.update(d)
+    return result
 
 dicts = struct(
-    add=_add,
+    add = _add,
 )