Updated all python modules to either have a max or specific version.

requirements.txt

@@ -1,21 +1,21 @@
 colorama==0.3.9
-PySerial>=2.7
-PrettyTable>=0.7.2
-Jinja2>=2.7.3
-IntelHex>=1.3
-junit-xml
-pyYAML
+pyserial>=3,<=3.4
+prettytable==0.7.2
+Jinja2>=2.7.3,<=2.10
+intelhex>=1.3,<=2.2.1
+junit-xml==1.8
+pyYAML==3.13
 urllib3[secure]==1.23
-requests
-mbed-ls>=1.5.1,==1.*
-mbed-host-tests>=1.1.2
-mbed-greentea>=0.2.24
-beautifulsoup4>=4
-fuzzywuzzy>=0.11
-pyelftools>=0.24
-jsonschema>=2.6
-future>=0.16.0
-six>=1.11.0
+requests==2.19.1
+mbed-ls>=1.5.1,<1.7
+mbed-host-tests>=1.1.2,<=1.5
+mbed-greentea>=0.2.24,<=1.5
+beautifulsoup4>=4,<=4.6.3
+fuzzywuzzy>=0.11,<=0.17
+pyelftools>=0.24,<=0.25
+jsonschema==2.6.0
+future==0.16.0
+six==1.11.0
 git+https://github.com/armmbed/manifest-tool.git@v1.4.6
 mbed-cloud-sdk==2.0.1
-icetea>=1.0.2,<2
+icetea>=1.0.2,<1.1