Address Dependabot alerts (#16)

* Bump guava.version to 24.1.1-jre
* Bump log4j.version to 2.13.3

Author: tr1ck3r

pom.xml

@@ -6,14 +6,14 @@
 
     <groupId>com.venafi.vcert.sdk</groupId>
     <artifactId>vcert-java</artifactId>
-    <version>0.1.3</version>
+    <version>0.1.4</version>
 
     <properties>
         <lombok.version>1.18.6</lombok.version>
         <bouncycastle.version>1.61</bouncycastle.version>
         <feign.version>10.4.0</feign.version>
-        <guava.version>23.0</guava.version>
-        <log4j.version>2.11.2</log4j.version>
+        <guava.version>24.1.1-jre</guava.version>
+        <log4j.version>2.13.3</log4j.version>
         <junit.version>5.3.1</junit.version>
         <mockito.version>2.25.1</mockito.version>
         <wiremock.version>2.22.0</wiremock.version>
@@ -157,4 +157,4 @@
         </repository>
     </repositories>
 
-</project>
+</project>