Switch to Redis for all caching.

// FREEBIE

src/main/java/org/whispersystems/textsecuregcm/configuration/MemcacheConfiguration.java

@@ -1,46 +0,0 @@
-/**
- * Copyright (C) 2013 Open WhisperSystems
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package org.whispersystems.textsecuregcm.configuration;
-
-import com.fasterxml.jackson.annotation.JsonProperty;
-import org.hibernate.validator.constraints.NotEmpty;
-
-public class MemcacheConfiguration {
-
-  @NotEmpty
-  @JsonProperty
-  private String servers;
-
-  @JsonProperty
-  private String user;
-
-  @JsonProperty
-  private String password;
-
-
-  public String getServers() {
-    return servers;
-  }
-
-  public String getUser() {
-    return user;
-  }
-
-  public String getPassword() {
-    return password;
-  }
-}

src/main/java/org/whispersystems/textsecuregcm/configuration/RedisConfiguration.java

@@ -21,7 +21,7 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import org.hibernate.validator.constraints.NotEmpty;
 import org.hibernate.validator.constraints.URL;
 
-public class DirectoryConfiguration {
+public class RedisConfiguration {
 
   @JsonProperty
   @NotEmpty