Implemented Observable#toCompletable

[stealthcode]

No description provided.

[stealthcode]

Addresses part of #3443

[akarnokd]

There are no items involved with Completable.

[akarnokd]

rx.internal.operators.OnSubscribeCompletableTest > testShouldUseUnsafeSubscribeInternallyNotSubscribe FAILED
    java.lang.AssertionError
        at org.junit.Assert.fail(Assert.java:92)
        at org.junit.Assert.assertTrue(Assert.java:43)
        at org.junit.Assert.assertFalse(Assert.java:68)
        at org.junit.Assert.assertFalse(Assert.java:79)
        at rx.internal.operators.OnSubscribeCompletableTest.testShouldUseUnsafeSubscribeInternallyNotSubscribe(OnSubscribeCompletableTest.java:96)

The Completable.fromObservable needs to change to unsafeSubscribe.

[stealthcode]

Thanks @akarnokd

[akarnokd]

👍

[stevegury]

👍