add travis and appveyor requirements

.travis.yml

@@ -186,3 +186,9 @@ before_install:
     else
       pip install beautysh;
     fi
+  # terraform
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
+      brew install terraform;
+    else
+      docker pull hashicorp/terraform;
+    fi

appveyor.yml

@@ -98,6 +98,10 @@ install:
   - cinst emacs -y
   - where emacs
 
+  # terraform
+  - cinst terraform -y
+  - where terraform
+
   # FIXME: Enable allowEmptyChecksums, until someone fixes the checksum issue of php
   - choco feature enable -n allowEmptyChecksums
   # PHP