Readme updates: new logo (helidon-io#13)

* Change README logo to latest project logo

* Shrink logo a bit

Author: barchetta

.gitignore

@@ -17,3 +17,6 @@ user.txt
 nb-configuration.xml
 node_modules/
 node/
+*.swp
+.gradle/
+build/

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-    <img src="./etc/images/helidon_cloud_sticker.png" height="250">
+    <img src="./etc/images/Primary_logo_blue.png" height="180">
 </p>
 <p align="center">
     <a href="https://github.com/oracle/helidon/tags">