Ruby: fix bug (#36)

* fix ruby

* skip rbenv/ruby-build

src/ruby/install.sh

@@ -192,13 +192,14 @@ fi
 find_version_from_git_tags RUBY_VERSION "https://github.com/ruby/ruby" "tags/v" "_"
 
 # Just install Ruby if RVM already installed
-if [ -d "/usr/local/rvm" ]; then
+if [ rvm --version != ""]; then
     echo "Ruby Version Manager already exists."
     if [ "${RUBY_VERSION}" != "none" ]; then
         echo "Installing specified Ruby version."
-        su ${USERNAME} -c "&& rvm install ruby ${RUBY_VERSION}"
+        su ${USERNAME} -c "rvm install ruby ${RUBY_VERSION}"
     fi
     SKIP_GEM_INSTALL="false"
+    SKIP_RBENV_RBUILD="true"
 else
     # Install RVM
     receive_gpg_keys RVM_GPG_KEYS
@@ -240,6 +241,7 @@ fi
 updaterc "if ! grep rvm_silence_path_mismatch_check_flag \$HOME/.rvmrc > /dev/null 2>&1; then echo 'rvm_silence_path_mismatch_check_flag=1' >> \$HOME/.rvmrc; fi\nsource /usr/local/rvm/scripts/rvm > /dev/null 2>&1"
 
 # Install rbenv/ruby-build for good measure
+if [ ${SKIP_RBENV_RBUILD} != "true"] ; then
     git clone --depth=1 \
         -c core.eol=lf \
         -c core.autocrlf=false \
@@ -263,6 +265,7 @@ if [ "${USERNAME}" != "root" ]; then
         chown -R ${USERNAME} /home/${USERNAME}/.rbenv
         ln -s /usr/local/share/ruby-build /home/${USERNAME}/.rbenv/plugins/ruby-build
     fi
+fi
 
 # Clean up
 source /usr/local/rvm/scripts/rvm