ARROW-1640: Fix HTTPS failures in cmake / libcurl caused by ca-certif…

…icates clash

See discussion in #1155

This seems to have done the trick, here is the Travis CI build running on my fork: https://travis-ci.org/wesm/arrow/builds/283203983

I will merge this as soon as it passes so that other PRs can rebase and stop failing

Author: Wes McKinney <wes.mckinney@twosigma.com>

Closes #1160 from wesm/fix-openssl-issues and squashes the following commits:

e218025 [Wes McKinney] Fix conda update statement
b2e3da1 [Wes McKinney] Do not install additional stuff in the root conda env
abb048e [Wes McKinney] Use ca-certificates from defaults

ci/travis_before_script_cpp.sh

@@ -47,6 +47,10 @@ if [ "$ARROW_TRAVIS_USE_TOOLCHAIN" == "1" ]; then
         curl \
         thrift-cpp \
         ninja
+
+  # HACK(wesm): We started experiencing OpenSSL failures when Miniconda was
+  # updated sometime on October 2 or October 3
+  conda update -y -p $CPP_TOOLCHAIN ca-certificates -c defaults
 fi
 
 if [ $TRAVIS_OS_NAME == "osx" ]; then

ci/travis_install_conda.sh

@@ -44,8 +44,3 @@ conda config --set remote_connect_timeout_secs 12
 conda config --add channels https://repo.continuum.io/pkgs/free
 conda config --add channels conda-forge
 conda info -a
-
-# faster builds, please
-conda install -y nomkl
-
-conda install --y conda-build jinja2 anaconda-client cmake curl