Standardize on the same capitalization pattern

Inside of mixing capitalization in title sections just
be consistent and capitalize the first word and then
have the rest of the title be lower cased.

Change-Id: I1170ab2ee3d5d3801ec4022d1c81d8173cbdd8df

doc/source/arguments_and_results.rst

@@ -1,4 +1,3 @@
-
 ==========================
 Atom Arguments and Results
 ==========================
@@ -37,12 +36,12 @@ those ways to accomplish your desired usage pattern.
     from taskflow import task
 
 
-Arguments Specification
+Arguments specification
 =======================
 
 There are different ways to specify the task argument ``requires`` set.
 
-Arguments Inference
+Arguments inference
 -------------------
 
 Task arguments can be inferred from arguments of the |task.execute| method of
@@ -130,7 +129,7 @@ passed to |task.execute| method as ``vm_name``, value from ``vm_image_id`` is
 passed as ``vm_image_id``, and value from ``admin_key_name`` is passed as
 ``admin_key_name`` parameter in ``kwargs``.
 
-Manually Specifying Requirements
+Manually specifying requirements
 --------------------------------
 
 **Why:** It is often useful to manually specify the requirements of a task,
@@ -187,7 +186,7 @@ avoid invalid argument mappings.
 
 .. make vim sphinx highlighter happy**
 
-Results Specification
+Results specification
 =====================
 
 In python, function results are not named, so we can not infer what a task
@@ -197,7 +196,7 @@ and it is typically (but not always) desirable to make those results accessible
 to other tasks. To accomplish this the task specifies names of those values via
 its ``provides`` task constructor parameter or other method (see below).
 
-Returning One Value
+Returning one value
 -------------------
 
 If task returns just one value, ``provides`` should be string -- the
@@ -212,8 +211,8 @@ name of the value.
     >>> TheAnswerReturningTask(provides='the_answer').provides
     set(['the_answer'])
 
-Returning Tuple
----------------
+Returning a tuple
+-----------------
 
 For a task that returns several values, one option (as usual in python) is to
 return those values via a ``tuple``.
@@ -252,8 +251,8 @@ and passed to the |task.revert| method).
     warning is printed to logs and if use of such parameter is attempted a
     ``NotFound`` exception is raised.
 
-Returning Dictionary
---------------------
+Returning a dictionary
+----------------------
 
 Another option is to return several values as a dictionary (aka a ``dict``).
 
@@ -293,7 +292,7 @@ will be able to get elements from storage by name:
     parameters are left undefined: a warning is printed to logs and if use of
     such parameter is attempted a ``NotFound`` exception is raised.
 
-Default Provides
+Default provides
 ----------------
 
 As mentioned above, the default task base class provides nothing, which means
@@ -329,7 +328,7 @@ the task from other tasks in the flow (e.g. to avoid naming conflicts):
 
     BitsAndPiecesTask(provides=())
 
-Revert Arguments
+Revert arguments
 ================
 
 To revert a task engine calls its |task.revert| method. This method
@@ -372,7 +371,7 @@ task failed, exception:"`` and exception message on revert. If this task
 finished successfully, it will print ``"do_something returned"`` and
 representation of result.
 
-Retry Arguments
+Retry arguments
 ===============
 
 A Retry controller works with arguments in the same way as a Task. But it has

doc/source/inputs_and_outputs.rst

@@ -10,7 +10,7 @@ state. You may also opt to use the :doc:`persistence <persistence>` layer
 itself directly.
 
 -----------------------
-Flow Inputs and Outputs
+Flow inputs and outputs
 -----------------------
 
 Tasks accept inputs via task arguments and provide outputs via task results
@@ -62,7 +62,7 @@ task.
    and outputs.
 
 ------------------
-Engine and Storage
+Engine and storage
 ------------------
 
 The storage layer is how an engine persists flow and task details (for more

doc/source/notifications.rst

@@ -26,7 +26,7 @@ provides means to write your own listeners, which can be more convenient than
 using raw callbacks.
 
 --------------------------------------
-Receiving Notifications with Callbacks
+Receiving notifications with callbacks
 --------------------------------------
 
 To manage notifications instances of
@@ -34,7 +34,7 @@ To manage notifications instances of
 
 .. autoclass:: taskflow.utils.misc.Notifier
 
-Flow Notifications
+Flow notifications
 ------------------
 
 To receive notification on flow state changes use
@@ -67,7 +67,7 @@ To receive notification on flow state changes use
    woof
    Flow 'cat-dog' transition to state SUCCESS
 
-Task Notifications
+Task notifications
 ------------------
 
 To receive notification on task state changes use
@@ -146,12 +146,12 @@ For example, this is how you can use
    taskflow.engines.action_engine.engine.SingleThreadedActionEngine: ... has moved task 'DogTalk' (...) into state 'SUCCESS' with result 'dog' (failure=False)
    taskflow.engines.action_engine.engine.SingleThreadedActionEngine: ... has moved flow 'cat-dog' (...) into state 'SUCCESS'
 
-Basic Listener
+Basic listener
 --------------
 
 .. autoclass:: taskflow.listeners.base.ListenerBase
 
-Printing and Logging Listeners
+Printing and logging listeners
 ------------------------------
 
 .. autoclass:: taskflow.listeners.base.LoggingBase
@@ -160,7 +160,7 @@ Printing and Logging Listeners
 
 .. autoclass:: taskflow.listeners.printing.PrintingListener
 
-Timing Listener
+Timing listener
 ---------------
 
 .. autoclass:: taskflow.listeners.timing.TimingListener