add Scala 3.0.0-M3 to crossbuild

Author: SethTisue

.travis.yml

@@ -7,6 +7,7 @@ language: scala
 scala:
  - 2.13.4
  - 3.0.0-M2
+ - 3.0.0-M3
 
 env:
  - ADOPTOPENJDK=8

core/src/main/scala/scala/collection/parallel/ParMapLike.scala

@@ -168,7 +168,7 @@ self =>
  def splitter = filtered.splitter
  override def contains(key: K) = self.contains(key) && p(key)
  def get(key: K) = if (!p(key)) None else self.get(key)
- def seq = self.seq.view.filterKeys(p).to(Map)
+ def seq = self.seq.view.filterKeys(p).to(collection.Map)
  def size = filtered.size
  override def knownSize = filtered.knownSize
  def + [U >: V](kv: (K, U)): ParMap[K, U] = ParMap[K, U]() ++ this + kv
@@ -182,7 +182,7 @@ self =>
  override def knownSize = self.knownSize
  override def contains(key: K) = self.contains(key)
  def get(key: K) = self.get(key).map(f)
- def seq = self.seq.view.mapValues(f).to(Map)
+ def seq = self.seq.view.mapValues(f).to(collection.Map)
  def + [U >: S](kv: (K, U)): ParMap[K, U] = ParMap[K, U]() ++ this + kv
  def - (key: K): ParMap[K, S] = ParMap[K, S]() ++ this - key
  }