Remove manual install of requirements.txt from circleci test, which is now handled by mbed CLI

Author: screamerbg

circle.yml

@@ -7,7 +7,6 @@ test:
         - mbed config -G protocol ssh
         - cd .tests && mbed new new-test
         - cd .tests/new-test && mbed ls
-        - cd .tests/new-test/mbed-os && pip install -r requirements.txt
         - cd .tests/new-test && mbed compile --source=. --source=mbed-os/TESTS/integration/basic -j 0
         - cd .tests/new-test && mbed test --compile -n tests-integration-threaded_blinky -j 0
         - cd .tests && mbed import https://developer.mbed.org/teams/Morpheus/code/mbed-Client-Morpheus-hg hg-test