deprecate live variable APIs (#113)

Author: wangjoshuah

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -285,13 +285,15 @@ public void track(@Nonnull String eventName,
 
     //======== live variable getters ========//
 
+    @Deprecated
     public @Nullable
     String getVariableString(@Nonnull String variableKey,
                              @Nonnull String userId,
                              boolean activateExperiment) throws UnknownLiveVariableException {
         return getVariableString(variableKey, userId, Collections.<String, String>emptyMap(), activateExperiment);
     }
 
+    @Deprecated
     public @Nullable
     String getVariableString(@Nonnull String variableKey,
                              @Nonnull String userId,
@@ -332,13 +334,15 @@ String getVariableString(@Nonnull String variableKey,
         return variable.getDefaultValue();
     }
 
+    @Deprecated
     public @Nullable
     Boolean getVariableBoolean(@Nonnull String variableKey,
                                @Nonnull String userId,
                                boolean activateExperiment) throws UnknownLiveVariableException {
         return getVariableBoolean(variableKey, userId, Collections.<String, String>emptyMap(), activateExperiment);
     }
 
+    @Deprecated
     public @Nullable
     Boolean getVariableBoolean(@Nonnull String variableKey,
                                @Nonnull String userId,
@@ -354,13 +358,15 @@ Boolean getVariableBoolean(@Nonnull String variableKey,
         return null;
     }
 
+    @Deprecated
     public @Nullable
     Integer getVariableInteger(@Nonnull String variableKey,
                                @Nonnull String userId,
                                boolean activateExperiment) throws UnknownLiveVariableException {
         return getVariableInteger(variableKey, userId, Collections.<String, String>emptyMap(), activateExperiment);
     }
 
+    @Deprecated
     public @Nullable
     Integer getVariableInteger(@Nonnull String variableKey,
                                @Nonnull String userId,
@@ -381,13 +387,15 @@ Integer getVariableInteger(@Nonnull String variableKey,
         return null;
     }
 
+    @Deprecated
     public @Nullable
     Double getVariableDouble(@Nonnull String variableKey,
                              @Nonnull String userId,
                              boolean activateExperiment) throws UnknownLiveVariableException {
         return getVariableDouble(variableKey, userId, Collections.<String, String>emptyMap(), activateExperiment);
     }
 
+    @Deprecated
     public @Nullable
     Double getVariableDouble(@Nonnull String variableKey,
                              @Nonnull String userId,
@@ -588,6 +596,7 @@ private EventType getEventTypeOrThrow(ProjectConfig projectConfig, String eventN
      * @throws UnknownLiveVariableException if there are no event types in the current project config with the given
      * name
      */
+    @Deprecated
     private LiveVariable getLiveVariableOrThrow(ProjectConfig projectConfig, String variableKey)
         throws UnknownLiveVariableException {