samples: tensorflow: remove requirements.txt from magic wand sample

Removes the requirements.txt from the training directory of the
magic wand sample as it is causing issues in CI. Updates README.md
to explicitly state the Python packages listed in requirements.txt.

Signed-off-by: Lauren Murphy <lauren.murphy@intel.com>
diff --git a/samples/modules/tensorflow/magic_wand/train/README.md b/samples/modules/tensorflow/magic_wand/train/README.md
index 55f1617..04f11fe 100644
--- a/samples/modules/tensorflow/magic_wand/train/README.md
+++ b/samples/modules/tensorflow/magic_wand/train/README.md
@@ -47,7 +47,7 @@
 Use the following command to install the required dependencies:
 
 ```shell
-pip install -r requirements.txt
+pip install numpy==1.16.2 tensorflow==2.0.0-beta1
 ```
 
 There are two ways to train the model:
diff --git a/samples/modules/tensorflow/magic_wand/train/requirements.txt b/samples/modules/tensorflow/magic_wand/train/requirements.txt
deleted file mode 100644
index c83b8a4..0000000
--- a/samples/modules/tensorflow/magic_wand/train/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-numpy==1.16.2
-tensorflow==2.0.0-beta1