Attempt to pass Travis test on pypy

- supress progress bar by pip when running pypy as this
  seems to crash the test on Travis:
  https://travis-ci.org/celery/celery/jobs/60549687

- this prevents dev.txt from being properly installed and the
  result is tests failing with import errors

tox.ini

@@ -48,7 +48,7 @@ deps = -r{toxinidir}/requirements/default.txt
        -r{toxinidir}/requirements/dev.txt
 setenv = C_DEBUG_TEST = 1
 commands = {toxinidir}/extra/release/removepyc.sh {toxinidir}
-           pip install -U -r{toxinidir}/requirements/dev.txt
+           pip install -q -U -r{toxinidir}/requirements/dev.txt
            nosetests -xsv --with-coverage --cover-inclusive --cover-erase []
 
 [testenv:pypy3]
@@ -59,7 +59,7 @@ deps = -r{toxinidir}/requirements/default.txt
        -r{toxinidir}/requirements/dev.txt
 setenv = C_DEBUG_TEST = 1
 commands = {toxinidir}/extra/release/removepyc.sh {toxinidir}
-           pip install -U -r{toxinidir}/requirements/dev.txt
+           pip install -q -U -r{toxinidir}/requirements/dev.txt
            nosetests -xsv --with-coverage --cover-inclusive --cover-erase []
 
 [testenv:docs]