Added note about Java 8 support (#1494)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 1.1.1 
 
+### Java 11 Required from v1.2
+
+From v1.2, Pantheon will require Java 11.  That is, Pantheon on Java 8 will no longer be supported.
+
 ### Additions and Improvements 
 
 - [GraphQL](https://docs.pantheon.pegasys.tech/en/latest/Pantheon-API/GraphQL/) [\#1311](https://github.com/PegaSysEng/pantheon/pull/1311) (thanks to [zyfrank](https://github.com/zyfrank))

docs/Installation/Build-From-Source.md

@@ -9,6 +9,8 @@ description: Building Pantheon from source code
 
 !!!important
     Pantheon requires Java 8+ to compile; earlier versions are not supported.
+    
+    From v1.2, Pantheon will require Java 11.  That is, Pantheon on Java 8 will no longer be supported.
 
 * [Git](https://git-scm.com/downloads) or [GitHub Desktop](https://desktop.github.com/)
 

docs/Installation/Install-Binaries.md

@@ -62,6 +62,8 @@ pantheon --help
     Pantheon is currently supported only on 64-bit versions of Windows, and requires a 64-bit version of JDK/JRE. 
     We recommend that you also remove any 32-bit JDK/JRE installations.
     
+    From v1.2, Pantheon will require Java 11.  That is, Pantheon on Java 8 will no longer be supported.
+    
 !!! note "Linux Open File Limit"
     If synchronizing to MainNet on Linux or other chains with large data requirements, increase the maximum 
     number of open files allowed using `ulimit`. If the open files limit is not high enough, a `Too many open files` RocksDB exception occurs.