prep for release

Increment version number to 1.5.1

Increment version number to 1.5.0

Increment version number to 1.4.0

Increment version number to 1.3.3

remove cleanup script

Increment version number to 1.3.1

Increment version number to 1.3.0

Increment version number to 1.2.7

Increment version number to 1.2.6