Fix dir doc typo error

Change-Id: I74de73e8f21ce44abbfa293369c774834d105c80

doc/source/devref/alembic_migrations.rst

@@ -355,7 +355,7 @@ and "contract" categories, as well as some data migrations.  the ``op.create_tab
 directive is an "expand"; it may be run safely while the old version of the
 application still runs, as the old code simply doesn't look for this table.
 The ``op.drop_constraint`` and ``op.drop_column`` directives are
-"contract" directives (the drop column moreso than the drop constraint); running
+"contract" directives (the drop column more so than the drop constraint); running
 at least the ``op.drop_column`` directives means that the old version of the
 application will fail, as it will attempt to access these columns which no longer
 exist.

doc/source/devref/db_models.rst

@@ -33,8 +33,8 @@ Structure of Model Definitions
 ------------------------------
 
 We have decided to move all models definitions to neutron/db/models/
-with no futher nesting after that point. The deprecation method to move
-models is already been added to avoid breakage of third party plugins using
+with no further nesting after that point. The deprecation method to move
+models has already been added to avoid breakage of third party plugins using
 those models. All relocated models need to use deprecate method that
 will generate a warning and return new class for use of old class. Some
 examples of relocated models [2] and [3]. In future if you define new models

doc/source/devref/rpc_callbacks.rst

@@ -272,7 +272,7 @@ belong to the same resource type, a single push RPC message is sent; if the list
 contains objects of different resource types, resources of each type are grouped
 and sent separately, one push RPC message per type. On the receiver side,
 resources in a list always belong to the same type. In other words, a server-side
-push of a list of heterogenous objects will result into N messages on bus and
+push of a list of heterogeneous objects will result into N messages on bus and
 N client-side callback invocations, where N is the number of unique resource
 types in the given list, e.g. L(A, A, B, C, C, C) would be fragmented into
 L1(A, A), L2(B), L3(C, C, C), and each list pushed separately.

doc/source/stadium/governance.rst

@@ -49,7 +49,7 @@ team.
 In fact, it became harder and harder to ensure consistency in the APIs,
 architecture, design, implementation and testing of the overarching project;
 all aspects of software development, like documentation, integration, release
-management, maintainance, and upgrades started to being neglected for some
+management, maintenance, and upgrades started to being neglected for some
 projects and that led to some unhappy experiences.
 
 The point about uniform APIs is particularly important, because the Neutron