Remove deprecated free() calls (#1925)

Replaced with the standard close()

wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java

@@ -53,11 +53,6 @@ public class I2C implements AutoCloseable {
     HAL.report(tResourceType.kResourceType_I2C, deviceAddress);
   }
 
-  @Deprecated
-  public void free() {
-    close();
-  }
-
   @Override
   public void close() {
     I2CJNI.i2CClose(m_port);

wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java

@@ -105,10 +105,6 @@ public abstract class RobotBase implements AutoCloseable {
     return m_threadId;
   }
 
-  @Deprecated
-  public void free() {
-  }
-
   @Override
   public void close() {
   }

wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotDrive.java

@@ -653,11 +653,6 @@ public class RobotDrive extends MotorSafety implements AutoCloseable {
     m_maxOutput = maxOutput;
   }
 
-  @Deprecated
-  public void free() {
-    close();
-  }
-
   /**
    * Free the speed controllers if they were allocated locally.
    */

wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java

@@ -50,12 +50,6 @@ public class SPI implements AutoCloseable {
     HAL.report(tResourceType.kResourceType_SPI, port.value);
   }
 
-
-  @Deprecated
-  public void free() {
-    close();
-  }
-
   @Override
   public void close() {
     if (m_accum != null) {