Ensure that the buck-built core library has no third party dependencies.

Because every dep we add makes it harder for people to implement their
own version. And it's not necessary.

Author: shs96c

java/client/src/org/openqa/selenium/BUCK

@@ -60,10 +60,8 @@ java_library(name = 'core',
     ':platform',
     ':primitives',
     '//java/client/src/org/openqa/selenium/interactions:core',
-    '//java/client/src/org/openqa/selenium/io:io',
     '//java/client/src/org/openqa/selenium/logging:api',
     '//java/client/src/org/openqa/selenium/security:security',
-    "//third_party/java/httpcomponents:httpclient",
   ],
   visibility = [
     '//java/client/src/org/openqa/selenium/interactions:interactions',