Cleanup Sandbox code

Remove unused code and methods.

Library/Homebrew/dev-cmd/test.rb

@@ -91,7 +91,7 @@ module Homebrew
         end
 
         Utils.safe_fork do
-          if Sandbox.test?
+          if Sandbox.available?
             sandbox = Sandbox.new
             f.logs.mkpath
             sandbox.record_log(f.logs/"test.sandbox.log")

Library/Homebrew/formula_installer.rb

@@ -753,7 +753,7 @@ class FormulaInstaller
     ].concat(build_argv)
 
     Utils.safe_fork do
-      if Sandbox.formula?(formula)
+      if Sandbox.available?
         sandbox = Sandbox.new
         formula.logs.mkpath
         sandbox.record_log(formula.logs/"build.sandbox.log")
@@ -922,7 +922,7 @@ class FormulaInstaller
     ]
 
     Utils.safe_fork do
-      if Sandbox.formula?(formula)
+      if Sandbox.available?
         sandbox = Sandbox.new
         formula.logs.mkpath
         sandbox.record_log(formula.logs/"postinstall.sandbox.log")

Library/Homebrew/sandbox.rb

@@ -10,18 +10,6 @@ class Sandbox
     OS.mac? && File.executable?(SANDBOX_EXEC)
   end
 
-  def self.formula?(_)
-    return false unless available?
-
-    !Homebrew.args.no_sandbox?
-  end
-
-  def self.test?
-    return false unless available?
-
-    !Homebrew.args.no_sandbox?
-  end
-
   def initialize
     @profile = SandboxProfile.new
   end

Library/Homebrew/test/sandbox_spec.rb

@@ -12,16 +12,6 @@ describe Sandbox do
     skip "Sandbox not implemented." unless described_class.available?
   end
 
-  specify "#formula?" do
-    f = formula { url "foo-1.0" }
-    expect(described_class).to be_formula(f), "Formulae should be sandboxed."
-  end
-
-  specify "#test?" do
-    ENV.delete("HOMEBREW_NO_SANDBOX")
-    expect(described_class).to be_test, "Tests should be sandboxed unless --no-sandbox was passed."
-  end
-
   specify "#allow_write" do
     subject.allow_write file
     subject.exec "touch", file