Update copyright

Practically should make it 2020 at this rate, whoops

(cherry picked from commit ff76f2b95a)

api/src/main/java/com/lishid/openinv/util/StringMetric.java

@@ -12,21 +12,6 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
- * *
- * Copyright (C) 2014 - 2018 Simmetrics Authors
- * Copyright (C) 2010 The Guava Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
  */
 
 package com.lishid.openinv.util;