Fixed rs-api dependency error

Applied fix found in gradle/gradle#3065

Error details from build log:
```
FAILURE: Build failed with an exception.

* What went wrong:
Could not resolve all dependencies for configuration ':marklogic-rdf4j:compile'.
> Could not determine artifacts for javax.ws.rs:javax.ws.rs-api:2.1
   > Could not HEAD 'https://jcenter.bintray.com/javax/ws/rs/javax.ws.rs-api/2.1/javax.ws.rs-api-2.1.$%7Bpackaging.type%7D'. Received status code 400 from server: Bad Request
```

marklogic-rdf4j/build.gradle

@@ -46,7 +46,9 @@ dependencies {
     compile('com.marklogic:marklogic-client-api:4.2.0') {
         exclude(group: 'org.slf4j')
         exclude(group: 'ch.qos.logback')
+        exclude(group: 'javax.ws.rs')
     }
+    compile "javax.ws.rs:javax.ws.rs-api:2.1@jar"
     compile('org.slf4j:slf4j-api:1.7.10')
     compile "ch.qos.logback:logback-classic:$logbackVersion"
     compile "org.slf4j:jcl-over-slf4j:$slf4jVersion"