Bumps version to v0.4.3.
Merge branch 'release/v0.4.3' into develop
Adds support for subcaches. Resolves #20.
Adds spacing to FileCache.__init__() code.
Adds code to raise ValueError when using 'cache' as a subcache name.
Bumps version to v0.4.4.
Bumps version to v0.4.4.
Merge branch 'release/v0.4.4'