Update to 2018_v4 image and new build system. (#598)

* Revert "Force OpenCV to 3.1.0 (#602)"

This reverts commit 50ed55e8e2.

* Removes Simulation

* Removes old build system

* Removes old gtest

* Adds new gmock and gtest

* Updates to new ni-libraries

* removes MyRobot (to be replaced)

* moves files to new location

* Adds new sim backend and new test executables

* updates .styleguide and .gitignore

* Changes cpp WPILibVersion to a function

MSVC throws an AV with the old version.

* Disables USBCamera on all systems except for linux

* 2018 NI Libraries

* New build system

wpilibcIntegrationTests/src/FRCUserProgram/cpp/BuiltInAccelerometerTest.cpp

@@ -0,0 +1,30 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "BuiltInAccelerometer.h"  // NOLINT(build/include_order)
+
+#include "Timer.h"
+#include "gtest/gtest.h"
+
+using namespace frc;
+
+static constexpr double kAccelerationTolerance = 0.1;
+/**
+ * There's not much we can automatically test with the on-board accelerometer,
+ * but checking for gravity is probably good enough to tell that it's working.
+ */
+TEST(BuiltInAccelerometerTest, Accelerometer) {
+  BuiltInAccelerometer accelerometer;
+
+  /* The testbench sometimes shakes a little from a previous test.  Give it
+          some time. */
+  Wait(1.0);
+
+  ASSERT_NEAR(0.0, accelerometer.GetX(), kAccelerationTolerance);
+  ASSERT_NEAR(1.0, accelerometer.GetY(), kAccelerationTolerance);
+  ASSERT_NEAR(0.0, accelerometer.GetZ(), kAccelerationTolerance);
+}