simplify settings.gradle by tutteli's settings plugin

- rename rootProject to arrow (this way we can benefit of a common
  prefix)
- apply the ch.tutteli.gradle.settings plugin
  - simplify includes with the include extension

settings.gradle

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2017 The Arrow Authors
+ *
+ * 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 CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+rootProject.name = "arrow"
+
+buildscript {
+    gradle.ext.tutteli_plugins_version = '0.4.0'
+    repositories {
+        maven { url "https://plugins.gradle.org/m2/" }
+    }
+    dependencies {
+        classpath "ch.tutteli:tutteli-gradle-settings:$gradle.ext.tutteli_plugins_version"
+    }
+}
+
+apply plugin: 'ch.tutteli.settings'
+
+//noinspection GroovyAssignabilityCheck
+include {
+    modules {
+
+        core {
+            _ 'annotations'
+            _ 'annotations-processor'
+            _ 'annotations-processor-test'
+            _ 'core'
+            _ 'data'
+            _ 'examples'
+            _ 'free'
+            _ 'instances'
+            _ 'kindedj'
+            _ 'mtl'
+            _ 'syntax'
+            _ 'test'
+            _ 'typeclasses'
+            _ 'validation'
+        }
+
+        effects {
+            _ 'effects'
+            _ 'effects-rx2'
+            _ 'effects-kotlinx-coroutines'
+        }
+
+        folder('recursion-schemes') {
+            _ 'recursion'
+        }
+
+        docs {
+            _ 'docs'
+        }
+
+        optics {
+            _ 'optics'
+        }
+
+        dagger {
+            _ 'dagger'
+            _ 'dagger-effects'
+            _ 'dagger-effects-kotlinx-coroutines'
+        }
+    }
+}