add Scala 3.0.0-M3 to crossbuild

.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
   }