Fixed working directory for dependency/consumer builds

Always pushd/popd project directory when executing project steps (#128)

* Always pushd/popd project directory when executing project steps

* Fixed cmake paths to be absolute

* Fixed macos-11

Added support for bashrc per container

v0.8.18

Fix release build for php docker images (#125)

New PHP docker images

v0.8.17

Removed redundant php installs and added phpbrew use to /etc/environm…

add check-submodules action

New check-submodules action (#119)

Checks each submodule:
- avoid accidental rollback.
- avoid accidentally using a submodule's branch.
- enforce that all submodules (except s2n and aws-lc) are using a tagged release.
  -  for s2n and aws-lc, enforce that they're at least using a commit on the main branch. I'm not enforcing tagged releases for these submodules since they're not repos that our team controls.

To use this action, add the following to a workflow:
```
  check-submodules:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout Source
      uses: actions/checkout@v2
      with:
        submodules: true
        fetch-depth: 0
    - name: Check Submodules
      uses: awslabs/aws-crt-builder/.github/actions/check-submodules
  ```

Fixes for swift docker images, CentOS support

Fixes for swift (#116)

* Only export compiler if CC/CXX are not specified

* Reduce what's installed on the swift centos docker image

* Added support for differentiating centos from manylinux

* Trimmed down swift docker images

Swift 5.4 and Build Variants support

update to swift 5.4 (#114)

* update to swift 5.4

* updated to use focal

Co-authored-by: Justin Boswell <boswej@amazon.com>

debian-stretch-arm32v5/arm32v7 images

Added python to docker image and AWS CLI (#112)

* Added python to docker image and AWS CLI

* Added unzip and tar

* Use aws cli v1 for arm

* debian doesn't need the apt repo

Swift Docker Image updates

add ssl packages to swift images for ci checks (#109)

* add ssl pacakges to swift images for ci checks

* only one package needed for ubuntu

Set CMAKE_BUILD_PARALLEL_LEVEL earlier (take 2)

not sure why previous release didn't create any artifacts... trying again

Set CMAKE_BUILD_PARALLEL_LEVEL earlier

trivial improvements (#105)

* set CMAKE_BUILD_PARALLEL_LEVEL before configuring
just in case some monster decides to build from within the configuration step (cough cough aws-c-cal/cmake/modules/aws-lc.cmake)

* more natural traversal order