Only define SimpleCov profile if nil

Upgrade SimpleCov.

On Ruby 2.0.0 specs fail because SimpleCov has already defined the
profile.

Only define the 'gem' profile if it has not been previously defined,
ie the first run.

spec/spec_helper.rb

@@ -9,11 +9,13 @@ def output_message(_message)
     end
   end
 
-  SimpleCov.adapters.define 'gem' do
-    add_filter '/spec/'
-    add_filter '/vendor/'
+  if SimpleCov.profiles[:gem].nil?
+    SimpleCov.profiles.define 'gem' do
+      add_filter '/spec/'
+      add_filter '/vendor/'
 
-    add_group 'Libraries', '/lib/'
+      add_group 'Libraries', '/lib/'
+    end
   end
 
   SimpleCov.minimum_coverage(84)

vcloud-core.gemspec

@@ -31,6 +31,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rake', '>= 12'
   s.add_development_dependency 'rspec', '>= 3.6'
   s.add_development_dependency 'rubocop', '~> 0.49.1'
-  s.add_development_dependency 'simplecov', '~> 0.7.1'
+  s.add_development_dependency 'simplecov', '~> 0.14.1'
   s.add_development_dependency 'vcloud-tools-tester'
 end