Update README.md

added documentation for SKYDNS_NAMESERVERS environment variable
Update README.md

Added SKYDNS_NAMESERVERS environment variable usage example
Merge pull request #55 from rojaro/patch-1

Update README.md
Add ca cert file argument
Merge pull request #56 from rojaro/master

Improved handling of environment variables and parameters
Merge
Small cleanups after merge:

rename getEnv to env and add ca-cert flag.
Dont sync cluster when https connect fails
Make a fatal when https connecto to etcd fails.
Add configurable GRAPHITE_PREFIX
Clean up indentation
add description about connecting to SSL-secured etcd
Merge pull request #61 from skurfuerst/patch-1

add description about connecting to SSL-secured etcd
Add error checking to graphiteServer
Merge pull request #60 from seanclerkin/master

Add configurable GRAPHITE_PREFIX
Also say we use env vars
fmt
removed left over code