Upgrade bintray

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189188071

build.gradle

@@ -18,7 +18,7 @@ buildscript {
     }
     }
     dependencies {
     dependencies {
         classpath 'com.android.tools.build:gradle:3.0.1'
         classpath 'com.android.tools.build:gradle:3.0.1'
-        classpath 'com.novoda:bintray-release:0.5.0'
+        classpath 'com.novoda:bintray-release:0.8.0'
     }
     }
     // Workaround for the following test coverage issue. Remove when fixed:
     // Workaround for the following test coverage issue. Remove when fixed:
     // https://code.google.com/p/android/issues/detail?id=226070
     // https://code.google.com/p/android/issues/detail?id=226070