rvm only works with login shell

.travis.yml

@@ -15,6 +15,10 @@ addons:
     packages:
       - tree
 
+before_install:
+  - rvm install 2.2.5
+  - rvm use 2.2.5
+
 # https://docs.travis-ci.com/user/customizing-the-build#Skipping-the-Installation-Step
 install: true  # if we don't skip install, ./gradlew assemble is invoked, but this task is not available.
 

bin/run-journey-test-from-ci.sh

@@ -7,8 +7,7 @@ modded_files=`echo $pr_files_json | bin/jq -r '.[].filename'`
 
 for file in $modded_files
   do if [[ $file == exercises* ]] || [[ $file == config.json ]]
-    then rvm install 2.2.5
-    rvm use 2.2.5
+    then
     for file2 in $modded_files
       do if [[ $file2 == exercises* ]]
         then modded_exercise=${file2#exercises/}