Update README.md and change Travis publish condition

Author: Anton Troshin

.travis.yml

@@ -8,7 +8,7 @@ jdk:
 stages:
   - name: build
   - name: publish
-    if: ((branch = master) AND (type != pull_request)) OR (tag IS present)
+    if: tag IS present
 
 jobs:
   include:

README.md

@@ -14,9 +14,15 @@ It helps to keep track of module dependencies and library version used in each m
 ## Installation
 Add the plugin as SBT dependency to your `project/plugins.sbt`
 
-```addSbtPlugin("com.supersonic" % "sonic-dependency-tree" % x)```
+```
+resolvers += Resolver.bintrayRepo("ironsonic", "sbt-plugins")
+
+addSbtPlugin("com.supersonic" % "sonic-dependency-tree" % "0.0.1")
+```
+
+Since it is an Auto Plugin, no need to explicitly enable it on the root project.
 
-On your root project enable plugin
+If you still wish to do so, you can do it like this:
 ``` scala
 lazy val root = (project in file("."))
   .enablePlugins(SonicDependencyTreePlugin)