Update copyright in README (#134)

Author: mpenick

README.md

@@ -129,16 +129,16 @@ cd /usr/local/src/php-driver
 
 ## Copyright
 
-Copyright 2015-2017 DataStax, Inc.
+© DataStax, Inc.
 
-Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+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
+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.