Initial come-back of TCK

Includes:
* Initial tests for spec rules for Publisher / Subscriber
* The Processor specs delegate to all pub / sub specs
* Additional Processor rules are REMAINS from the OLD TCK,
  and have not yet been pruned / cleaned up.
* Added travis to build; there is only one test which validates that all
  pub / sub rules are properly delegated to from the processor test.
* Tests now fail in isolation, previous TCK could cascade one test
  failure to multiple tests failing

Please review and share feedback, it's still a bit early and needs more polish.
The classes I would ask you to focus on are PublisherVerification and
SubscriberVerification.

Author: ktoso

.travis.yml

@@ -0,0 +1,3 @@
+language: java
+script: sbt test
+

tck/bin/.gitignore

@@ -0,0 +1,42 @@
+package org.reactivestreams.tck;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+public class Annotations {
+  private Annotations() {}
+
+  /**
+   * Used to mark tests for specification rules which were currently impossible to be implemented.
+   * For example tests like "Publisher SHOULD consider Subscription as ..." - is inherently hard to specifically test.
+   */
+  @Target(ElementType.METHOD)
+  @Retention(RetentionPolicy.SOURCE)
+  static @interface NotVerified {
+  }
+
+  /**
+   * Used to mark tests that MUST pass in all (even very restricted types of) Publishers / Subscribers.
+   */
+  @Target(ElementType.METHOD)
+  @Retention(RetentionPolicy.SOURCE)
+  static @interface Required {
+  }
+
+  /**
+   * Used to mark tests which may be skipped / not implemented by certain implementations.
+   * These tests can be skipped by returning null from the given factory method.
+   */
+  @Target(ElementType.METHOD)
+  @Retention(RetentionPolicy.SOURCE)
+  @interface Additional {
+    /** Description of situation when it's OK to not pass this test */
+    String value() default "";
+
+    /** Name of the method to be implemented (returning <em>not</em> {@code null}) if this test should be run. */
+    String implement() default "";
+  }
+
+}