Increment project version to 0.1.3

Changes since the last version:

- Added Clojars badge and Travis CI badge to README

- Small fix in log4j.properties

- Fixed a test helper that specifies a relative path to leiningen; it
  now assumes that an executable `lein2` can be found in PATH

project.clj

@@ -1,4 +1,4 @@
-(defproject io.mandoline/mandoline-core "0.1.2"
+(defproject io.mandoline/mandoline-core "0.1.3"
   :description
     "Mandoline is a distributed store for multi-dimensional arrays"
   :license {:name "Apache License, version 2.0"