Getting error at compile time Error: Execution fai

Question

After adding com.google.gdata:core:1.47.1 gradle dependency, now constantly getting build error like this.

Error:Execution failed for task ':packageAllDebugClassesForMultiDex'.
> java.util.zip.ZipException: duplicate entry: com/google/gdata/util/common/base/UnicodeEscaper$1.class

I excluded most of dependencies from com.google.gdata:core:1.47.1, here is gradle code.

compile('com.google.gdata:core:1.47.1') {
        exclude(group: 'javax.mail', module: 'mail')
        exclude(group: 'com.google.oauth-client', module: 'google-oauth-client-jetty')
    }

After googling come to know, my project having 2 jars (signpost-core-1.2.1.1.jar & com.google.gdata:core:1.47.1) which are having one common package (com.google.gdata.util.common.base).That is creating issue i think. I tried to exclude common package but no luck.