Checkstyle 8.1 (#584)

Added a few checks too:
- SimplifyBooleanExpression
- SimplifyBooleanReturn
- StringLiteralEquality
- UnnecessaryParentheses

wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java

@@ -96,12 +96,12 @@ public class PIDToleranceTest {
     assertFalse("Error was in tolerance when it should not have been. Error was "
         + m_pid.getAvgError(), m_pid.onTarget());
     //half of percent tolerance away from setPoint
-    m_inp.m_val = m_setPoint + (m_tolerance) / 200 * m_range;
+    m_inp.m_val = m_setPoint + m_tolerance / 200 * m_range;
     Timer.delay(1.0);
     assertTrue("Error was not in tolerance when it should have been. Error was "
         + m_pid.getAvgError(), m_pid.onTarget());
     //double percent tolerance away from setPoint
-    m_inp.m_val = m_setPoint + (m_tolerance) / 50 * m_range;
+    m_inp.m_val = m_setPoint + m_tolerance / 50 * m_range;
     Timer.delay(1.0);
     assertFalse("Error was in tolerance when it should not have been. Error was "
         + m_pid.getAvgError(), m_pid.onTarget());

wpilibj/src/test/java/edu/wpi/first/wpilibj/command/MockCommand.java

@@ -70,6 +70,8 @@ public class MockCommand extends Command {
   }
 
   /**
+   * Get what value the isFinished method will return.
+   *
    * @return what value the isFinished method will return.
    */
   public boolean isHasFinished() {
@@ -77,6 +79,8 @@ public class MockCommand extends Command {
   }
 
   /**
+   * Set what value the isFinished method will return.
+   *
    * @param hasFinished set what value the isFinished method will return.
    */
   public void setHasFinished(boolean hasFinished) {