travis: backport some install code / order from master for macOS.

.travis/install.sh

@@ -4,26 +4,28 @@ set -e
 set -x
 
 if [[ "$(uname -s)" == 'Darwin' ]]; then
-    # HOMEBREW_NO_AUTO_UPDATE=1
+    export HOMEBREW_NO_AUTO_UPDATE=1
     export HOMEBREW_LOGS=~/brew-logs
     export HOMEBREW_TEMP=~/brew-temp
     mkdir $HOMEBREW_LOGS
     mkdir $HOMEBREW_TEMP
-    # brew update
-    if [[ "${OPENSSL}" != "0.9.8" ]]; then
-        brew outdated openssl || brew upgrade openssl
-    fi
+    brew update > /dev/null
+    brew cleanup > /dev/null  # do this here, so it won't automatically trigger in the middle of other stuff
+    brew outdated pkg-config || brew upgrade pkg-config
+    # do NOT update openssl 1.0.x, brew will also update a lot of dependent pkgs (and their dependencies) then!
+    #brew outdated openssl || brew upgrade openssl
+    export PKG_CONFIG_PATH="/usr/local/opt/openssl@1.1/lib/pkgconfig:$PKG_CONFIG_PATH"
+    brew install readline
+    export PKG_CONFIG_PATH="/usr/local/opt/readline/lib/pkgconfig:$PKG_CONFIG_PATH"
+    brew install lz4
+    brew install xz  # required for python lzma module
+    brew install Caskroom/cask/osxfuse
 
+    brew outdated pyenv || brew upgrade pyenv
     if which pyenv > /dev/null; then
         eval "$(pyenv init -)"
     fi
 
-    brew install lz4
-    brew install xz  # required for python lzma module
-    brew outdated pyenv || brew upgrade pyenv
-    brew install pkg-config
-    brew install Caskroom/cask/osxfuse
-
     case "${TOXENV}" in
         py34)
             pyenv install 3.4.5