Remove clover.xml from the gitignore.

We no longer use the clover report for code coverage validation.
Only try to remove temp files if directory exists.

`glob()` returns false if the directory doesn't exist which causes
warnings when running this.  We only need to run it if the directory
exists.
Add a docker/fig based build.
Merge pull request #8 from nubs/master

Add a docker/fig based build.