Add exec (#10)

* Add exec

* Fix linux tests

* unnecessary dependency

* Dont prefix ExecOptions with I

* Consistency nits

* Respond to feedback

* Add toolrunner explanatory quote

* Format

packages/exec/src/interfaces.ts

@@ -0,0 +1,45 @@
+import * as stream from 'stream'
+/**
+ * Interface for exec options
+ */
+export interface ExecOptions {
+  /** optional working directory.  defaults to current */
+  cwd?: string
+
+  /** optional envvar dictionary.  defaults to current process's env */
+  env?: {[key: string]: string}
+
+  /** optional.  defaults to false */
+  silent?: boolean
+
+  /** optional out stream to use. Defaults to process.stdout */
+  outStream?: stream.Writable
+
+  /** optional err stream to use. Defaults to process.stderr */
+  errStream?: stream.Writable
+
+  /** optional. whether to skip quoting/escaping arguments if needed.  defaults to false. */
+  windowsVerbatimArguments?: boolean
+
+  /** optional.  whether to fail if output to stderr.  defaults to false */
+  failOnStdErr?: boolean
+
+  /** optional.  defaults to failing on non zero.  ignore will not fail leaving it up to the caller */
+  ignoreReturnCode?: boolean
+
+  /** optional. How long in ms to wait for STDIO streams to close after the exit event of the process before terminating. defaults to 10000 */
+  delay?: number
+
+  /** optional. Listeners for output. Callback functions that will be called on these events */
+  listeners?: {
+    stdout?: (data: Buffer) => void
+
+    stderr?: (data: Buffer) => void
+
+    stdline?: (data: string) => void
+
+    errline?: (data: string) => void
+
+    debug?: (data: string) => void
+  }
+}