fix(rubocop): fix remaining errors manually

```bash
letsencrypt-formula$ rubocop -d
...
Inspecting 5 files
Scanning /home/imran/Salt/formulas/letsencrypt-formula/Gemfile
.Scanning /home/imran/Salt/formulas/letsencrypt-formula/bin/kitchen
.Scanning /home/imran/Salt/formulas/letsencrypt-formula/test/integration/deb/controls/letsencrypt_spec.rb
CScanning /home/imran/Salt/formulas/letsencrypt-formula/test/integration/git/controls/letsencrypt_spec.rb
CScanning /home/imran/Salt/formulas/letsencrypt-formula/test/integration/rpm/controls/letsencrypt_spec.rb
C

Offenses:

test/integration/deb/controls/letsencrypt_spec.rb:13:94: C: Metrics/LineLength: Line is too long. [95/88]
  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
                                                                                             ^^
test/integration/deb/controls/letsencrypt_spec.rb:45:89: C: Metrics/LineLength: Line is too long. [91/88]
  its('content') { should match 'deb http://deb.debian.org/debian stretch-backports main' }
                                                                                        ^^^
test/integration/git/controls/letsencrypt_spec.rb:17:94: C: Metrics/LineLength: Line is too long. [95/88]
  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
                                                                                             ^^
test/integration/rpm/controls/letsencrypt_spec.rb:14:94: C: Metrics/LineLength: Line is too long. [95/88]
  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
                                                                                             ^^

5 files inspected, 4 offenses detected
```

test/integration/deb/controls/letsencrypt_spec.rb

@@ -10,7 +10,9 @@
   it { should be_grouped_into 'root' }
   it { should be_readable }
   its('size') { should be > 1 }
-  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
+  its('content') do
+    should match 'server = https://acme-staging.api.letsencrypt.org/directory'
+  end
   its('content') { should match 'authenticator = webroot' }
 end
 
@@ -42,5 +44,7 @@
   it { should be_grouped_into 'root' }
   it { should be_readable }
   its('size') { should be > 1 }
-  its('content') { should match 'deb http://deb.debian.org/debian stretch-backports main' }
+  its('content') do
+    should match 'deb http://deb.debian.org/debian stretch-backports main'
+  end
 end

test/integration/git/controls/letsencrypt_spec.rb

@@ -14,6 +14,8 @@
   it { should be_grouped_into 'root' }
   it { should be_readable }
   its('size') { should be > 1 }
-  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
+  its('content') do
+    should match 'server = https://acme-staging.api.letsencrypt.org/directory'
+  end
   its('content') { should match 'authenticator = standalone' }
 end

test/integration/rpm/controls/letsencrypt_spec.rb

@@ -11,7 +11,9 @@
   it { should be_readable }
   its('size') { should be > 1 }
 
-  its('content') { should match 'server = https://acme-staging.api.letsencrypt.org/directory' }
+  its('content') do
+    should match 'server = https://acme-staging.api.letsencrypt.org/directory'
+  end
   its('content') { should match 'authenticator = webroot' }
 end