Pin s3am on toil-box (resolves #206)

Also fixes a `parse_version = <function at ...>` entry that had snuck into the generated version.py in each sub project.

version.py

@@ -2,16 +2,20 @@
 bd2k_python_lib_dep = 'bd2k-python-lib>=1.11.dev6'
 boto_dep = 'boto==2.38.0'
 fabric_dep = 'Fabric==1.10.3'
-s3am_dep = 's3am>=2.0a1.dev99,<2.1'
+s3am_dep = 's3am==2.0a1.dev105'
 
-if __name__ == '__main__':
+
+def main( ):
     import os
     from pkg_resources import parse_version
-
     is_release_build = not parse_version( cgcloud_version ).is_prerelease
     suffix = '' if is_release_build else '.dev' + os.environ.get( 'BUILD_NUMBER', '0' )
     for name, value in globals( ).items( ):
         if name.startswith( 'cgcloud_' ):
             value += suffix
-        if name.split('_')[-1] in ('dep', 'version' ):
+        if name.split( '_' )[ -1 ] in ('dep', 'version'):
             print "%s='%s'" % (name, value)
+
+
+if __name__ == '__main__':
+    main( )