Add "context" to examples

A context is now required for the execute method to enable
cancellation.

Thanks to @josegonzalez for bringing this to my attention

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Enable use of DisableStdioBuffer

Previously, DisableStdioBuffer was added in #16, however
was not consumed or used, as reported in #19.

DisableStdioBuffer can now be set, if you only want to stream
directly to stdio, or want to capture the output to your own
writer without buffering.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Allow for spaces in command

Prior to this change, Windows users who had a space in the
path to a command would encounter errors.

Tested with a unit test which failed before commenting out
code in exec.go to split out the command and arguments if
a space was within the command.

This is a breaking change and downstream users should make
sure they populate Command and Args separately.

alexellis/arkade#117

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Update examples and usage

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

feat: Add context aware V2 API

This new v2 module requires context, so that cancellation can be
propogated correctly to sub-commands.

Some additional streamlining of the code to reduce the number of
`exec.Execute` calls.

The new behavior is covered by additional tests and the package should
have 98% coverage.

Signed-off-by: Lucas Roesler <[email protected]>

Add go module

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Support hooking in a reader for stdin

This will be used in arkade to pipe the input to kubectl apply.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Fix issue with overlapping envs

Fixes an issue where custom environment variable was overriden
by host value causing a clash.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add option: StreamStdio

The StreamStdio option, when set to true, streams output to
STDIO. When set to false the user can only access the output
from the result.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Set exit-code when non-zero

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>