Add improvements to "Building a connector the hard way"

docs/connector-development/tutorials/build-a-connector-the-hard-way.md

@@ -156,6 +156,7 @@ README.md
 acceptance-test-config.yml
 acceptance-test-docker.sh
 build.gradle
+source.py
 spec.json
 ```
 
@@ -261,6 +262,9 @@ Then we'll add the `check_method`:
 
 ```python
 import requests
+import datetime
+from datetime import date
+from datetime import timedelta
 
 def _call_api(ticker, token):
     today = date.today()
@@ -284,6 +288,8 @@ def check(config):
     print(json.dumps(output_message))
 ```
 
+In order to run this code later, be sure to `pip install requests` in your local virtual environment. `datetime` should already be included in your Python installation. 
+
 Lastly we'll extend the `run` method to accept the `check` command and call the `check` method. First we'll add a helper method for reading input:
 
 ```python
@@ -314,6 +320,12 @@ elif command == "check":
     check(config)
 ```
 
+Then we need to update our list of available commands:
+
+```python
+        log("Invalid command. Allowable commands: [spec, check]")
+```
+
 This results in the following `run` method.
 
 ```python
@@ -349,7 +361,9 @@ def run(args):
     sys.exit(0)
 ```
 
-and that should be it. Let's test our new method:
+and that should be it.
+
+Let's test our new method:
 
 ```bash
 $ python source.py check --config secrets/valid_config.json
@@ -416,6 +430,12 @@ elif command == "discover":
     discover()
 ```
 
+We need to update our list of available commands:
+
+```python
+        log("Invalid command. Allowable commands: [spec, check, discover]")
+```
+
 You may be wondering why `config` is a required input to `discover` if it's not used. This is done for consistency: the Airbyte Specification requires `--config` as an input to `discover` because many sources require it \(e.g: to discover the tables available in a Postgres database, you must supply a password\). So instead of guessing whether the flag is required depending on the connector, we always assume it is required, and the connector can choose whether to use it.
 
 The full run method is now below:
@@ -526,10 +546,6 @@ First, let's create a configured catalog `fullrefresh_configured_catalog.json` t
 Then we'll define the `read` method in `source.py`:
 
 ```python
-import datetime
-from datetime import date
-from datetime import timedelta
-
 def read(config, catalog):
     # Assert required configuration was provided
     if "api_key" not in config or "stock_ticker" not in config:
@@ -590,6 +606,12 @@ elif command == "read":
     read(config, configured_catalog)
 ```
 
+and: 
+
+```python
+        log("Invalid command. Allowable commands: [spec, check, discover, read]")
+```
+
 this yields the following `run` method:
 
 ```python
@@ -915,7 +937,7 @@ Then we can run the image using:
 docker run airbyte/source-stock-ticker-api:dev
 ```
 
-to run any of our commands, we'll need to mount all the inputs into the Docker container first, then refer to their _mounted_ paths when invoking the connector. For example, we'd run `check` or `read` as follows:
+To run any of our commands, we'll need to mount all the inputs into the Docker container first, then refer to their _mounted_ paths when invoking the connector. This allows the connector to access your secrets without having to build them into the container. For example, we'd run `check` or `read` as follows:
 
 ```bash
 $ docker run airbyte/source-stock-ticker-api:dev spec
@@ -975,6 +997,7 @@ tests:
 Then from the connector module directory run
 
 ```bash
+chmod 755 acceptance-test-docker.sh
 ./acceptance-test-docker.sh
 ```
 
@@ -1058,7 +1081,7 @@ airbyte-server      | Version: dev
 airbyte-server      | 
 ```
 
-After you see the above banner printed out in the terminal window where you are running `docker-compose up`, visit [http://localhost:8000](http://localhost:8000) in your browser. 
+After you see the above banner printed out in the terminal window where you are running `docker-compose up`, visit [http://localhost:8000](http://localhost:8000) in your browser and log in with the default credentials: username `airbyte` and password `password`. 
 
 If this is the first time using the Airbyte UI, then you will be prompted to go through a first-time wizard. To skip it, click the "Skip Onboarding" button.