Handle dict extras in Voluptuous Schema

Not sure if schema requirements changed but it is no longer valid to
use:

  Schema({}, extra=True)

The docs say that should be avoided and instead you should use:

  Schema(dict)

To indicate a dict that can have any key: value pairs. Additionally
extra=True appears to be replaced with extra=ALLOW_EXTRA so update that
in cases where we have some subset of desired keys.

Change-Id: I3dc966dae534416f2b601ec8d299e1d0e3651e7b
diff --git a/zuul/configloader.py b/zuul/configloader.py
index 5e88ee7..8d5f14f 100644
--- a/zuul/configloader.py
+++ b/zuul/configloader.py
@@ -582,7 +582,7 @@
                               'email': str,
                               'older-than': str,
                               'newer-than': str,
-                              }, extra=True)
+                              }, extra=vs.ALLOW_EXTRA)
 
         require = {'approval': to_list(approval),
                    'open': bool,
diff --git a/zuul/driver/gerrit/gerritconnection.py b/zuul/driver/gerrit/gerritconnection.py
index e18daa9..f8d47d2 100644
--- a/zuul/driver/gerrit/gerritconnection.py
+++ b/zuul/driver/gerrit/gerritconnection.py
@@ -819,5 +819,5 @@
 
 
 def getSchema():
-    gerrit_connection = v.Any(str, v.Schema({}, extra=True))
+    gerrit_connection = v.Any(str, v.Schema(dict))
     return gerrit_connection
diff --git a/zuul/driver/gerrit/gerritreporter.py b/zuul/driver/gerrit/gerritreporter.py
index d132d65..0ade355 100644
--- a/zuul/driver/gerrit/gerritreporter.py
+++ b/zuul/driver/gerrit/gerritreporter.py
@@ -48,5 +48,5 @@
 
 
 def getSchema():
-    gerrit_reporter = v.Any(str, v.Schema({}, extra=True))
+    gerrit_reporter = v.Any(str, v.Schema(dict))
     return gerrit_reporter
diff --git a/zuul/driver/gerrit/gerrittrigger.py b/zuul/driver/gerrit/gerrittrigger.py
index c678bce..70c65fd 100644
--- a/zuul/driver/gerrit/gerrittrigger.py
+++ b/zuul/driver/gerrit/gerrittrigger.py
@@ -82,14 +82,14 @@
 def getSchema():
     def toList(x):
         return v.Any([x], x)
-    variable_dict = v.Schema({}, extra=True)
+    variable_dict = v.Schema(dict)
 
     approval = v.Schema({'username': str,
                          'email-filter': str,
                          'email': str,
                          'older-than': str,
                          'newer-than': str,
-                         }, extra=True)
+                         }, extra=v.ALLOW_EXTRA)
 
     gerrit_trigger = {
         v.Required('event'):
diff --git a/zuul/driver/git/gitconnection.py b/zuul/driver/git/gitconnection.py
index 9c8d658..67f195c 100644
--- a/zuul/driver/git/gitconnection.py
+++ b/zuul/driver/git/gitconnection.py
@@ -59,5 +59,5 @@
 
 
 def getSchema():
-    git_connection = v.Any(str, v.Schema({}, extra=True))
+    git_connection = v.Any(str, v.Schema(dict))
     return git_connection
diff --git a/zuul/driver/smtp/smtpconnection.py b/zuul/driver/smtp/smtpconnection.py
index 6338cd5..56ca240 100644
--- a/zuul/driver/smtp/smtpconnection.py
+++ b/zuul/driver/smtp/smtpconnection.py
@@ -58,5 +58,5 @@
 
 
 def getSchema():
-    smtp_connection = v.Any(str, v.Schema({}, extra=True))
+    smtp_connection = v.Any(str, v.Schema(dict))
     return smtp_connection
diff --git a/zuul/driver/sql/sqlconnection.py b/zuul/driver/sql/sqlconnection.py
index 31bc13a..4b1b1a2 100644
--- a/zuul/driver/sql/sqlconnection.py
+++ b/zuul/driver/sql/sqlconnection.py
@@ -101,5 +101,5 @@
 
 
 def getSchema():
-    sql_connection = v.Any(str, v.Schema({}, extra=True))
+    sql_connection = v.Any(str, v.Schema(dict))
     return sql_connection
diff --git a/zuul/driver/zuul/zuultrigger.py b/zuul/driver/zuul/zuultrigger.py
index bb7c04e..c0c2fb3 100644
--- a/zuul/driver/zuul/zuultrigger.py
+++ b/zuul/driver/zuul/zuultrigger.py
@@ -63,7 +63,7 @@
                          'email': str,
                          'older-than': str,
                          'newer-than': str,
-                         }, extra=True)
+                         }, extra=v.ALLOW_EXTRA)
 
     zuul_trigger = {
         v.Required('event'):