Correct style errors identified by the latest version of RuboCop
diff --git a/src/ruby/.rubocop_todo.yml b/src/ruby/.rubocop_todo.yml
index d5bb55e..d9fe0a5 100644
--- a/src/ruby/.rubocop_todo.yml
+++ b/src/ruby/.rubocop_todo.yml
@@ -1,42 +1,30 @@
 # This configuration was generated by `rubocop --auto-gen-config`
-# on 2015-01-16 02:30:04 -0800 using RuboCop version 0.28.0.
+# on 2015-04-14 09:35:44 -0700 using RuboCop version 0.29.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 3
-# Lint/UselessAssignment:
-#  Enabled: false
-
-# Offense count: 33
+# Offense count: 32
 Metrics/AbcSize:
-  Max: 39
-
-# Offense count: 3
-# Configuration parameters: CountComments.
-Metrics/ClassLength:
-  Max: 231
+  Max: 36
 
 # Offense count: 2
-Metrics/CyclomaticComplexity:
-  Max: 8
+# Configuration parameters: CountComments.
+Metrics/ClassLength:
+  Max: 183
 
-# Offense count: 36
+# Offense count: 35
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
-  Max: 37
+  Max: 36
 
-# Offense count: 8
+# Offense count: 7
 # Configuration parameters: CountKeywordArgs.
 Metrics/ParameterLists:
   Max: 8
 
-# Offense count: 2
-Metrics/PerceivedComplexity:
-  Max: 10
-
-# Offense count: 7
+# Offense count: 6
 # Configuration parameters: AllowedVariables.
 Style/GlobalVars:
   Enabled: false
@@ -50,3 +38,7 @@
 # Configuration parameters: Methods.
 Style/SingleLineBlockParams:
   Enabled: false
+
+# Offense count: 1
+Style/StructInheritance:
+  Enabled: false
diff --git a/src/ruby/spec/channel_spec.rb b/src/ruby/spec/channel_spec.rb
index 31e38d7..d471ff5 100644
--- a/src/ruby/spec/channel_spec.rb
+++ b/src/ruby/spec/channel_spec.rb
@@ -58,7 +58,7 @@
     it 'does not take a hash with bad values as channel args' do
       blk = construct_with_args(symbol: Object.new)
       expect(&blk).to raise_error TypeError
-      blk = construct_with_args('1' => Hash.new)
+      blk = construct_with_args('1' => {})
       expect(&blk).to raise_error TypeError
     end
 
diff --git a/src/ruby/spec/client_server_spec.rb b/src/ruby/spec/client_server_spec.rb
index 1a2afbe..68af79f 100644
--- a/src/ruby/spec/client_server_spec.rb
+++ b/src/ruby/spec/client_server_spec.rb
@@ -192,11 +192,11 @@
   describe 'from client => server' do
     before(:example) do
       n = 7  # arbitrary number of metadata
-      diff_keys_fn = proc { |i| [sprintf('k%d', i), sprintf('v%d', i)] }
+      diff_keys_fn = proc { |i| [format('k%d', i), format('v%d', i)] }
       diff_keys = Hash[n.times.collect { |x| diff_keys_fn.call x }]
-      null_vals_fn = proc { |i| [sprintf('k%d', i), sprintf('v\0%d', i)] }
+      null_vals_fn = proc { |i| [format('k%d', i), format('v\0%d', i)] }
       null_vals = Hash[n.times.collect { |x| null_vals_fn.call x }]
-      same_keys_fn = proc { |i| [sprintf('k%d', i), [sprintf('v%d', i)] * n] }
+      same_keys_fn = proc { |i| [format('k%d', i), [format('v%d', i)] * n] }
       same_keys = Hash[n.times.collect { |x| same_keys_fn.call x }]
       symbol_key = { a_key: 'a val' }
       @valid_metadata = [diff_keys, same_keys, null_vals, symbol_key]
@@ -242,11 +242,11 @@
   describe 'from server => client' do
     before(:example) do
       n = 7  # arbitrary number of metadata
-      diff_keys_fn = proc { |i| [sprintf('k%d', i), sprintf('v%d', i)] }
+      diff_keys_fn = proc { |i| [format('k%d', i), format('v%d', i)] }
       diff_keys = Hash[n.times.collect { |x| diff_keys_fn.call x }]
-      null_vals_fn = proc { |i| [sprintf('k%d', i), sprintf('v\0%d', i)] }
+      null_vals_fn = proc { |i| [format('k%d', i), format('v\0%d', i)] }
       null_vals = Hash[n.times.collect { |x| null_vals_fn.call x }]
-      same_keys_fn = proc { |i| [sprintf('k%d', i), [sprintf('v%d', i)] * n] }
+      same_keys_fn = proc { |i| [format('k%d', i), [format('v%d', i)] * n] }
       same_keys = Hash[n.times.collect { |x| same_keys_fn.call x }]
       symbol_key = { a_key: 'a val' }
       @valid_metadata = [diff_keys, same_keys, null_vals, symbol_key]
diff --git a/src/ruby/spec/server_spec.rb b/src/ruby/spec/server_spec.rb
index a47e484..bb566d1 100644
--- a/src/ruby/spec/server_spec.rb
+++ b/src/ruby/spec/server_spec.rb
@@ -152,7 +152,7 @@
     it 'does not take a hash with bad values as channel args' do
       blk = construct_with_args(symbol: Object.new)
       expect(&blk).to raise_error TypeError
-      blk = construct_with_args('1' => Hash.new)
+      blk = construct_with_args('1' => {})
       expect(&blk).to raise_error TypeError
     end