scala sbt控制台，包括回显

我试图在scala应用程序中使用带有slf4j的logback。我在build.sbt中包含了以下内容

libraryDependencies += "org.slf4j" % "slf4j-api" % "1.7.5" 
libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.1.3"
libraryDependencies += "ch.qos.logback" % "logback-core" % "1.1.3"

我试图调用

sbt控制台-Dlogback.configurationFile=logback.xml-DLOG\u DIR=。

但是我在sbt类路径中看到了多个绑定（log4j和logback）

  SLF4J: Found binding in [jar:file:~/.ivy2/cache/org.slf4j/slf4j-log4j12/jars/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
  SLF4J: Found binding in [jar:file:~/.ivy2/cache/ch.qos.logback/logback-classic/jars/logback-classic-1.1.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
  SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.

我不确定log4j jar是如何被拉到.ivy2的

build.sbt

libraryDependencies += "org.slf4j" % "slf4j-api" % "1.7.5" 
libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.1.3"
libraryDependencies += "ch.qos.logback" % "logback-core" % "1.1.3"

 libraryDependencies += "org.apache.spark" %% "spark-streaming" % "1.2.1"
 libraryDependencies += "org.apache.spark" %% "spark-core" % "1.2.1"
 libraryDependencies += "com.datastax.spark" %% "spark-cassandra-connector" % "1.2.1"
 libraryDependencies += "com.datastax.spark" %% "spark-cassandra-connector-java" % "1.2.1"
 libraryDependencies += "com.google.protobuf" % "protobuf-java" % "2.5.0"
 libraryDependencies += "spark.jobserver" % "job-server-api" % "0.5.0" % "provided"
 libraryDependencies += "net.liftweb" %% "lift-json" % "2.5.3"
 libraryDependencies += "org.scalatest" %% "scalatest" % "2.2.4" % "test"
 libraryDependencies += "com.github.nscala-time" %% "nscala-time" % "2.0.0"
 libraryDependencies += "net.sf.opencsv" % "opencsv" % "2.3"
 libraryDependencies += "org.slf4j" % "slf4j-api" % "1.7.5"
 libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.1.3"
 libraryDependencies += "ch.qos.logback" % "logback-core" % "1.1.3"

问题：

1） 我的build.sbt正在下载log4j吗

2） 如何确保slf4j仅在sbt控制台中与logback绑定