(#10099) Properly join commands from passed in array

Prior to this commit, the `Util::Powershell.execute_inline`
method didn't properly join the passed in command and instead attempted
to execute the array of strings. This commit updates that
behavior to join the command array prior to inserting it into the full
powershell command.

lib/vagrant/util/powershell.rb

@@ -132,6 +132,9 @@ module Vagrant
         if env = opts.delete(:env)
           env = env.map{|k,v| "$env:#{k}=#{v}"}.join(";") + "; "
         end
+
+        command = command.join(' ')
+
         c = [
           executable,
           "-NoLogo",

test/unit/vagrant/util/powershell_test.rb

@@ -215,6 +215,7 @@ describe Vagrant::Util::PowerShell do
     let(:exit_code){ 0 }
     let(:stdout){ "" }
     let(:stderr){ "" }
+    let(:command) { ["run", "--this", "custom-command"] }
 
     before do
       allow(described_class).to receive(:validate_install!)
@@ -223,7 +224,7 @@ describe Vagrant::Util::PowerShell do
 
     it "should validate installation before use" do
       expect(described_class).to receive(:validate_install!)
-      described_class.execute_inline("command")
+      described_class.execute_inline(command)
     end
 
     it "should include command to execute" do
@@ -232,7 +233,7 @@ describe Vagrant::Util::PowerShell do
         expect(comm.to_s).to include("custom-command")
         result
       end
-      described_class.execute_inline("custom-command")
+      described_class.execute_inline(command)
     end
 
     it "should accept custom environment" do
@@ -241,7 +242,7 @@ describe Vagrant::Util::PowerShell do
         expect(comm.to_s).to include("$env:TEST_KEY=test-value")
         result
       end
-      described_class.execute_inline("custom-command", env: {"TEST_KEY" => "test-value"})
+      described_class.execute_inline(command, env: {"TEST_KEY" => "test-value"})
     end
 
     it "should define a custom module path" do
@@ -250,11 +251,11 @@ describe Vagrant::Util::PowerShell do
         expect(comm.to_s).to include("$env:PSModulePath+';C:\\My-Path'")
         result
       end
-      described_class.execute_inline("custom-command", module_path: "C:\\My-Path")
+      described_class.execute_inline(command, module_path: "C:\\My-Path")
     end
 
     it "should return a result instance" do
-      expect(described_class.execute_inline("cmd")).to eq(result)
+      expect(described_class.execute_inline(command)).to eq(result)
     end
   end