Allow users to set their AWS profile

Motivation:
  - Currently the Serverless system does not allow you to access their
    sdk, hopefully that is coming soon
    serverless/serverless#1529
    This means that if a user has multiple AWS profiles setup they may
    be using something other than defualt to manage their Serverless
    framework. Since you cannot access the serverless config yet we
    should let them specify the profile to use when migrating.

Author: gwincr11

index.js

@@ -54,12 +54,17 @@ module.exports = function (S) {
                     description: 'Stage that dynamodb should be remotely executed'
                 }, {
                     option: 'table_prefix',
-                    shortcut: 'p',
+                    shortcut: 't',
                     description: 'Table name prefix'
                 }, {
                     option: 'table_suffix',
                     shortcut: 'x',
                     description: 'Table name suffix'
+                },
+                {
+                    option: 'profile',
+                    shortcut: 'p',
+                    description: 'aws profile'
                 }
                 ]
             });
@@ -78,12 +83,17 @@ module.exports = function (S) {
                     description: 'Stage that dynamodb should be remotely executed'
                 }, {
                     option: 'table_prefix',
-                    shortcut: 'p',
+                    shortcut: 't',
                     description: 'Table name prefix'
                 }, {
                     option: 'table_suffix',
                     shortcut: 'x',
                     description: 'Table name suffix'
+                },
+                {
+                    option: 'profile',
+                    shortcut: 'p',
+                    description: 'aws profile'
                 }]
             });
             S.addAction(this.remove.bind(this), {
@@ -204,6 +214,10 @@ module.exports = function (S) {
         execute(evt) {
             let self = this,
                 options = evt.options;
+            if(options.profile) {
+              AWS.config.credentials =
+                new AWS.SharedIniFileCredentials({ profile: options.profile });
+            }
             return new BbPromise(function (resolve, reject) {
                 let dynamodb = self.dynamodbOptions(options.stage, options.region),
                     tableOptions = self.tableOptions(options.table_prefix, options.table_suffix);
@@ -215,6 +229,11 @@ module.exports = function (S) {
         executeAll(evt) {
             let self = this,
                 options = evt.options;
+            if(options.profile) {
+              AWS.config.credentials =
+                new AWS.SharedIniFileCredentials({ profile: options.profile });
+            }
+
             return new BbPromise(function (resolve, reject) {
                 let dynamodb = self.dynamodbOptions(options.stage, options.region),
                     tableOptions = self.tableOptions(options.table_prefix, options.table_suffix);