Cleanup and clarification in README file

- environment setup requirements are more clearly outlined
- test setup and execution are now in one section instead of scattered through several sections
- test setup example can be used as-is for running CATs against bosh-lite

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
Add section about go dependencies to README

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
Vendor newer version of cmdtest

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
targeting org and space is now done by tests, not by user before running tests

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
Add information about Godep

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
Ignore compiled test files

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>
Readme contains more robust test setup steps

Signed-off-by: Alex Stupakov <astupakov@pivotallabs.com>