Deployment optimizations for reduced time to build and redeploys

[nickdenardis]

Reason for change

Build and deploys are now taking 4-5 minutes on average. This is far too much time to wait to install dependencies, test, package and ship the code to the server.

After adding timing to each of the tasks, it was discovered a few tasks were running multiple times, commands on the server were not optimized and the cleanup of previous releases was holding up the deploy from finishing.

The goal is to get deploys to happen in under 1-minute.

Changes

1. Dependencies are no longer cleared after each release so only incremental changes need to be installed
2. Composer and npm installs still happen twice (the first time to run the tests, the second time to package the release), this is still an incremental improvement and this will be optimized further in a next update
3. Moving files on the server uses an optimized rsync command for speed and reduced output noise
4. Moving previous releases on the server uses mv instead of cp for speed
5. Packaged releases are named by release hash to detect and skip rebuilds of redeploys
6. Cleaning up previous releases has been forked to another thread so it isn't blocking the deploy from finishing

This deploy script isn't the easiest to read, so each section modified now includes indentations for formatting.

Demo

1. First deploy is the previous benchmark
2. Second deploy is the non-primed cache version of this change
3. Thirs deploy is the primed cache redeploy

[coveralls]

coverage: 100.0%. remained the same
when pulling 1a01c22 on feature/deploy-optimizations
into a476907 on develop.