Only install fpm,rpm,boto if we need them

CHANGELOG.md

@@ -43,6 +43,7 @@ continue sending logs to /var/log/telegraf/telegraf.log.
 
 ### Bugfixes
 
+- [#1926](https://github.com/influxdata/telegraf/issues/1926): Fix toml unmarshal panic in Duration objects.
 - [#1746](https://github.com/influxdata/telegraf/issues/1746): Fix handling of non-string values for JSON keys listed in tag_keys.
 - [#1628](https://github.com/influxdata/telegraf/issues/1628): Fix mongodb input panic on version 2.2.
 - [#1733](https://github.com/influxdata/telegraf/issues/1733): Fix statsd scientific notation parsing

circle.yml

@@ -12,9 +12,6 @@ machine:
 dependencies:
   override:
     - docker info
-  post:
-    - gem install fpm
-    - sudo apt-get install -y rpm python-boto
 
 test:
   override:

scripts/circle-test.sh

@@ -75,6 +75,10 @@ cat telegraf-race | gzip > $CIRCLE_ARTIFACTS/telegraf-race.gz
 
 eval "git describe --exact-match HEAD"
 if [ $? -eq 0 ]; then
+    # install fpm (packaging dependency)
+    exit_if_fail gem install fpm
+    # install boto & rpm (packaging & AWS dependencies)
+    exit_if_fail sudo apt-get install -y rpm python-boto
     unset GOGC
     tag=$(git describe --exact-match HEAD)
     echo $tag