Remove H2 DB dependency

+ We provide a convenience config to spec use of in-memory h2 database as a datasource during initial / trial development.
+ H2 had been a dependency that was resolved @ outdated 1.x version with security vulnerabilities.
+ Remove dependency from hoist-core, replace with updated comment re. need to add back in at app-level using v2.x.
+ Update JDBC URL to workaround `value` as reserved word in H2 v2.x.

build.gradle

@@ -50,7 +50,6 @@ dependencies {
 
     runtimeOnly "org.glassfish.web:el-impl:2.2.1-b05"
     runtimeOnly "javax.xml.bind:jaxb-api:2.3.1"
-    runtimeOnly "com.h2database:h2"
 
     //--------------------
     // Hoist Additions

src/main/groovy/io/xh/hoist/configuration/RuntimeConfig.groovy

@@ -7,6 +7,8 @@
 
 package io.xh.hoist.configuration
 
+import org.hibernate.dialect.H2Dialect
+
 import static io.xh.hoist.util.InstanceConfigUtils.getInstanceConfig
 import static io.xh.hoist.util.Utils.withDelegate
 
@@ -18,8 +20,7 @@ import static io.xh.hoist.util.Utils.withDelegate
 class RuntimeConfig {
 
     /**
-     * All apps should call this from runtime.groovy
-     * to setup necessary default configurations
+     * All apps should call this from runtime.groovy to setup necessary default configurations
      */
     static void defaultConfig(Script script) {
         withDelegate(script) {
@@ -28,26 +29,30 @@ class RuntimeConfig {
     }
 
     /**
-     * Call this from runtime.groovy
-     * to setup an in memory H2 DB instead of
-     * a MySQL or SQL Server DB.  This H2 DB option
-     * is intended only for early stages of development,
-     * before a production ready DB has been set up.
+     * Call this from runtime.groovy to setup an in memory H2 DB instead of MySQL or SQL Server.
+     * This option is intended only for early stages of development, before a production-ready
+     * database has been provisioned. Data is transient, NOT intended for actual deployments!
+     *
+     * Note you will need to add a dependency to your app's build.gradle file:
+     *      `runtimeOnly "com.h2database:h2:2.2.224"` (check and use latest/suitable version).
      */
     static void h2Config(Script script) {
         withDelegate(script) {
             dataSource {
                 pooled = true
                 jmxExport = true
                 driverClassName = "org.h2.Driver"
+                dialect = H2Dialect
                 username = "sa"
                 password = ""
             }
             environments {
                 development {
                     dataSource {
                         dbCreate = "create-drop"
-                        url = "jdbc:h2:mem:devDb;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
+                        // `value` is a reserved word in H2 v2.x but used by Hoist AppConfig.
+                        // We can workaround with NON_KEYWORDS=VALUE in the JDBC URL below.
+                        url = "jdbc:h2:mem:devDb;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE;NON_KEYWORDS=VALUE"
                     }
                 }
             }