(maint) Address a few spec failures when running with facter 4

.gemspec

@@ -30,7 +30,7 @@ Gem::Specification.new do |s|
   s.require_paths = ["lib"]
   s.summary = "Puppet, an automated configuration management tool"
   s.specification_version = 3
-  s.add_runtime_dependency(%q<facter>, [">= 2.4.0", "< 4"])
+  s.add_runtime_dependency(%q<facter>, [">= 2.4.0", "< 5"])
   s.add_runtime_dependency(%q<hiera>, [">= 3.2.1", "< 4"])
   s.add_runtime_dependency(%q<semantic_puppet>, "~> 1.0")
   s.add_runtime_dependency(%q<fast_gettext>, "~> 1.1")

spec/unit/indirector/catalog/compiler_spec.rb

@@ -477,6 +477,7 @@ def a_request_that_contains(facts)
     end
 
     it "should add 'pe_serverversion' when PE" do
+      allow(File).to receive(:readable?).and_call_original
       allow(File).to receive(:readable?).with(pe_version_file).and_return(true)
       allow(File).to receive(:zero?).with(pe_version_file).and_return(false)
       allow(File).to receive(:read).and_call_original

spec/unit/provider/service/init_spec.rb

@@ -150,6 +150,7 @@
 
   describe "if the init script is present" do
     before :each do
+      allow(File).to receive(:directory?).and_call_original
       allow(File).to receive(:directory?).with("/service/path").and_return(true)
       allow(File).to receive(:directory?).with("/alt/service/path").and_return(true)
       allow(Puppet::FileSystem).to receive(:exist?).with("/service/path/myservice").and_return(true)

spec/unit/provider/service/openwrt_spec.rb

@@ -28,6 +28,7 @@
     allow(FileTest).to receive(:executable?).with('/etc/rc.common').and_return(true)
 
     # All OpenWrt tests operate on the init script directly. It must exist.
+    allow(File).to receive(:directory?).and_call_original
     allow(File).to receive(:directory?).with('/etc/init.d').and_return(true)
 
     allow(Puppet::FileSystem).to receive(:exist?).with('/etc/init.d/myservice').and_return(true)