move rvm use to 'test' section

circle.yml

@@ -22,7 +22,6 @@ dependencies:
     - sudo make install
     - sudo make themispp_install
     - sudo make pythemis_install
-    - rvm use system #switch to system ruby
     - sudo GEM_INSTALL_OPTIONS=--user-install make rubythemis_install
     - sudo make phpthemis_install
     - cd $HOME && git clone https://boringssl.googlesource.com/boringssl && cd boringssl && git checkout chromium-stable && mkdir build && cd build && cmake .. && make && cp decrepit/libdecrepit.a crypto/
@@ -42,6 +41,7 @@ test:
     # we should calculate coverage for gothemis and send report before sending coverage of main C part
     - '[ -z "$CIRCLE_PR_NUMBER" ] && ! [ -z "$COVERALLS_TOKEN" ] && cd $HOME/gopath/src/$GOTHEMIS_IMPORT && $HOME/gopath/bin/goveralls -v -service=circle-ci -repotoken=$COVERALLS_TOKEN || true'
     - sudo /sbin/ldconfig
+    - rvm use system #switch to system ruby
     - make test
     - valgrind build/tests/soter_test 2>&1 | grep "ERROR SUMMARY\|definitely lost\|indirectly lost\|possibly lost" | awk '{sum += $4} END {exit sum}'
     - valgrind build/tests/themis_test 2>&1 | grep "ERROR SUMMARY\|definitely lost\|indirectly lost\|possibly lost" | awk '{sum += $4} END {exit sum}'