Add RandomId and RandomIdOf (#288)

* Add RandomId helper

* Remove unused imports

* fix missing .flatten method in TestFrameworkApi

core/src/main/scala/com/evolutiongaming/catshelper/RandomId.scala

@@ -0,0 +1,18 @@
+package com.evolutiongaming.catshelper
+
+import cats.kernel.Eq
+import cats.{Order, Show}
+
+final case class RandomId(value: String) extends AnyVal {
+  override def toString = value
+}
+
+object RandomId {
+  implicit val eqRandomId: Eq[RandomId] = Eq.fromUniversalEquals
+
+  implicit val showRandomId: Show[RandomId] = Show.fromToString
+
+  implicit val orderingRandomId: Ordering[RandomId] = Ordering.by(_.value )
+
+  implicit val orderRandomId: Order[RandomId] = Order.fromOrdering
+}

core/src/main/scala/com/evolutiongaming/catshelper/RandomIdOf.scala

@@ -0,0 +1,19 @@
+package com.evolutiongaming.catshelper
+
+import java.util.UUID
+
+import cats.effect.Sync
+
+trait RandomIdOf[F[_]] {
+  def apply: F[RandomId]
+}
+
+object RandomIdOf {
+
+  def apply[F[_]](implicit fa: RandomIdOf[F]): RandomIdOf[F] = fa
+
+  def uuid[F[_] : Sync]: RandomIdOf[F] = new RandomIdOf[F] {
+
+    def apply = Sync[F].delay { RandomId(UUID.randomUUID().toString) }
+  }
+}

core/src/test/scala/com/evolutiongaming/catshelper/CatsHelperSpec.scala

@@ -1,6 +1,5 @@
 package com.evolutiongaming.catshelper
 
-import cats.effect.implicits._
 import cats.effect.kernel.Ref
 import cats.effect.unsafe.IORuntime
 import cats.effect.{IO, Resource}

core/src/test/scala/com/evolutiongaming/catshelper/RandomIdSpec.scala

@@ -0,0 +1,16 @@
+package com.evolutiongaming.catshelper
+
+import cats.effect.IO
+import com.evolutiongaming.catshelper.IOSuite._
+import org.scalatest.funsuite.AsyncFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class RandomIdSpec extends AsyncFunSuite with Matchers {
+  test("uuid apply") {
+    RandomIdOf
+      .uuid[IO]
+      .apply
+      .map { _.value should not be empty }
+      .run()
+  }
+}

core/src/test/scala/com/evolutiongaming/catshelper/ResourceBreakFlatMapChainTest.scala

@@ -3,7 +3,6 @@ package com.evolutiongaming.catshelper
 import cats.effect.kernel.Deferred
 import cats.effect.{IO, Resource}
 import cats.implicits._
-import cats.effect.implicits._
 import com.evolutiongaming.catshelper.CatsHelper._
 import com.evolutiongaming.catshelper.IOSuite._
 import org.scalatest.funsuite.AsyncFunSuite