Refactored to use StreamableWriter

Bumped the msgpack library to 2.0.1 (the 2.0.0 build was fubar)

exports/build.gradle

@@ -15,9 +15,9 @@ dependencies {
     compile 'org.slf4j:slf4j-api'
     compile 'com.beust:klaxon'
 
-    testCompile 'junit:junit:4.12'
-    testCompile 'org.hamcrest:hamcrest-library:1.3'
-    testCompile 'com.nhaarman:mockito-kotlin:1.5.0'
+    testCompile 'junit:junit'
+    testCompile 'org.hamcrest:hamcrest-library'
+    testCompile 'com.nhaarman:mockito-kotlin'
     testCompile project(path: ':core', configuration: 'testArtifacts')
     testCompile project(':cryptography-bc')
 }

exports/src/main/kotlin/ch/dissem/bitmessage/exports/ContactExport.kt

@@ -39,7 +39,7 @@ object ContactExport {
                     "subscribed" to it.isSubscribed,
                     "pubkey" to it.pubkey?.let {
                         val out = ByteArrayOutputStream()
-                        it.writeUnencrypted(out)
+                        it.writer().writeUnencrypted(out)
                         Base64.encodeToString(out.toByteArray())
                     },
                     "privateKey" to if (includePrivateKey) {