allows patch levels (ie 9.5.14) (#26)

* allows patch levels (ie 9.5.14)

    See http://rubular.com/r/2aiU6kIEG6

* make patch level optional

* only test major and minor versions

Author: ojongerius

controls/postgres_spec.rb

@@ -115,7 +115,7 @@
   title 'Use stable postgresql version'
   desc 'Use only community or commercially supported version of the PostgreSQL software. Do not use RC, DEVEL oder BETA versions in a production environment.'
   describe command('psql -V') do
-    its('stdout') { should match(/\b9\.[3-6]$|\b10\.5$/) }
+    its('stdout') { should match(/^psql\s\(PostgreSQL\)\s(9\.[3-6]|10\.5).*/) }
   end
   describe command('psql -V') do
     its('stdout') { should_not match(/RC/) }