Double whitespaces removed from README

Change-Id: Idc0ec69b237e487092237fa638fb4f40fb36e55c

README.md

@@ -23,7 +23,7 @@ The following interfaces are provided:
 
 - keystone-service: This is currently only used by Horizon/dashboard
   as its interaction with Keystone is different from other OpenStack API
-  services. That is, Horizon requests a Keystone role and token exists.  During
+  services. That is, Horizon requests a Keystone role and token exists. During
   a relation, Horizon requests its configured default role and Keystone
   responds with a token and the auth + admin ports on which Keystone is
   listening.
@@ -128,7 +128,7 @@ Network Space Support
 ---------------------
 
 This charm supports the use of Juju Network Spaces, allowing the charm to be
-bound to network space configurations managed directly by Juju.  This is only
+bound to network space configurations managed directly by Juju. This is only
 supported with Juju 2.0 and above.
 
 API endpoints can be bound to distinct network spaces supporting the network
@@ -164,7 +164,7 @@ Token Support
 -------------
 
 As the keystone charm supports multiple releases of the OpenStack software, it
-also supports two keystone token systems: UUID and Fernet.  The capabilities are:
+also supports two keystone token systems: UUID and Fernet. The capabilities are:
 
 - pre 'ocata': UUID tokens only.
 - ocata and pike: UUID or Fernet tokens, configured via the 'token-provider'
@@ -181,25 +181,25 @@ Questions](https://docs.openstack.org/keystone/pike/admin/identity-fernet-token-
 ### Theory of Operation
 
 In order to generate tokens, Fernet keys are used. These are generated by
-keystone and have an expiry date.  The key repository is a directory, and each
-key is an integer number, with the highest number being the primary key.  Key
-'0' is the staged key, that will be the next primary.  Other keys are secondary
+keystone and have an expiry date. The key repository is a directory, and each
+key is an integer number, with the highest number being the primary key. Key
+'0' is the staged key, that will be the next primary. Other keys are secondary
 keys.
 
 New tokens are only ever generated from the primary key, whilst the secondary
-keys are used to validate existing tokens.  The staging key is not used to
+keys are used to validate existing tokens. The staging key is not used to
 generate tokens but can be used to validate tokens as the staging key might be
 the new primary key on the master due to a rotation and the keys have not yet
 been synchronised across all the units.
 
 Fernet keys need to be rotated at periodic intervals, and the keys need to be
-synchronised to each of the other keystone units.  Keys should only be rotated
+synchronised to each of the other keystone units. Keys should only be rotated
 on the master keystone unit and must be synchronised *before* they are rotated
-again.  *Over rotation* occurs if a unit rotates its keys such that there is
+again. *Over rotation* occurs if a unit rotates its keys such that there is
 no suitable decoding key on another unit that can decode a token that has been
-generated on the master.  This happens if two key rotations are done on the
-master before a synchronisation has been successfully performed.  This should
-be avoided.  Over rotations can also cause validation keys to be removed
+generated on the master. This happens if two key rotations are done on the
+master before a synchronisation has been successfully performed. This should
+be avoided. Over rotations can also cause validation keys to be removed
 *before* a token's expiration which would result in failed validations.
 
 There are 3 parts to the **Key Rotation Strategy**:
@@ -208,8 +208,8 @@ There are 3 parts to the **Key Rotation Strategy**:
 2. The token lifespan
 3. The number of active keys
 
-There needs to be at least 3 keys as a minimum.  The actual number of keys is
-determined by the *token lifespan* and the *rotation frequency*.  The
+There needs to be at least 3 keys as a minimum. The actual number of keys is
+determined by the *token lifespan* and the *rotation frequency*. The
 *max_active_keys* must be one greater than the *token lifespan* / *rotation
 frequency*
 
@@ -223,7 +223,7 @@ To quote from the [FAQ](https://docs.openstack.org/keystone/queens/admin/identit
 
 In the keystone charm, the _rotation frequency_ is calculated
 automatically from the `token-expiration` and the `fernet-max-active-keys`
-configuration parameters.  For example, with an expiration of 24 hours and
+configuration parameters. For example, with an expiration of 24 hours and
 6 active keys, the rotation frequency is calculated as:
 
 
@@ -244,15 +244,15 @@ rotation frequency, do the opposite.
 NOTE: If the configuration parameters are used to significantly reduce the
 key lifetime, then it is possible to over-rotate the verification keys
 such that services will hold tokens that cannot be verified but haven't
-yet expired.  This should be avoided by only making small changes and
-verifying that current tokens will still be able to be verified.  In
+yet expired. This should be avoided by only making small changes and
+verifying that current tokens will still be able to be verified. In
 particular, `fernet-max-active-keys` affects the rotation time.
 
 ### Upgrades
 
 When an older keystone charm is upgraded to this version, NO change will
-occur to the token system.  That is, an ocata system will continue to use
-UUID tokens.  In order to change the token system to Fernet, change the
-`token-provider` configuration item to `fernet`.  This will switch the
-token system over.  There may be a small outage in the _control plane_,
+occur to the token system. That is, an ocata system will continue to use
+UUID tokens. In order to change the token system to Fernet, change the
+`token-provider` configuration item to `fernet`. This will switch the
+token system over. There may be a small outage in the _control plane_,
 but the running instances will be unaffected.