License h2 only under the MIT license

The intent of the original licensing text was to dual license under both
Apache 2.0 and MIT. As such, switching the license to only MIT is
permitted.

README.md

@@ -63,11 +63,3 @@ fn main() {
 **Is this an embedded Java SQL database engine?**
 
 [No](http://www.h2database.com).
-
-## License
-
-`h2` is primarily distributed under the terms of both the MIT license and the
-Apache License (Version 2.0), with portions covered by various BSD-like
-licenses.
-
-See LICENSE-APACHE, and LICENSE-MIT for details.