feat(docker): updated sdk installation in docker file

Author: kingsodigie

docker/Dockerfile

@@ -1,21 +1,25 @@
-#Import python runtime with desired python version
+#Import Python base image 
 FROM python:3-slim
 
 #Install Git
 RUN apt-get update && \
-    apt-get install -y git
+    apt-get install -y --no-install-recommends git && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
 
 #Clone SDK repo to app directory
 RUN git clone https://github.com/watson-developer-cloud/python-sdk.git
 
-#Set working directory to python-sdk
+#Install the SDK
+RUN pip install --upgrade ibm-watson
+
+# #Set working directory to python-sdk
 WORKDIR /python-sdk
 
-#Pip install dependencies for SDK
-RUN pip install --editable .
+#Install test dependencies and run tests to verify installation.
 RUN pip install -r requirements-dev.txt
 
-#Run tests to validate installation
-CMD [ "py.test" , "test" ]
+#Run tests to verify installation
+CMD ["py.test","test"]