Fix .travis.yml.

.travis.yml

@@ -1,7 +1,7 @@
 language: c
 script: asdf plugin-test python https://github.com/tuvistavie/asdf-python.git
 before_script:
-  - git clone https://github.com/tuvistavie/asdf.git --branch plugin-test asdf
+  - git clone https://github.com/tuvistavie/asdf.git --branch test-latest-version-install asdf
   - . asdf/asdf.sh
 os:
   - linux

bin/install

@@ -19,6 +19,7 @@ install_python() {
   # because we don't want to disturb current working dir
   (
     cd $(dirname $source_path)
+    echo $source_path
     tar zxf $source_path || exit 1
 
     cd "Python-${version}"