Adjusted silverstripe/framework dependency

Removed silverstripe/admin dependency

Aliased 2.0 branch as 2.0.x-dev

Set travis to 4.0 instead of just 4

.travis.yml

@@ -6,12 +6,12 @@ php:
   - 7.1
 
 env:
-  - DB=MYSQL CORE_RELEASE=4
+  - DB=MYSQL CORE_RELEASE=4.0
 
 matrix:
   include:
     - php: 7.1
-      env: DB=PGSQL CORE_RELEASE=4
+      env: DB=PGSQL CORE_RELEASE=4.0
 
 before_script:
   - git clone git://github.com/silverstripe/silverstripe-travis-support.git ~/travis-support

composer.json

@@ -12,8 +12,7 @@
 		}
 	],
 	"require": {
-		"silverstripe/admin": "^1.0@dev",
-		"silverstripe/framework": "^4.0@dev",
+		"silverstripe/framework": "~4.0",
 		"silverstripe/versioned": "^1.0"
 	},
 	"autoload": {
@@ -28,7 +27,7 @@
 	"extra": {
 		"installer-name": "sortablegridfield",
 		"branch-alias": {
-			"dev-master": "1.0.x-dev"
+			"dev-master": "2.0.x-dev"
 		}
 	}
 }