make processing of mac addresses case insensitive

[rconde01]

Description

Fixes WaitForNetIP when the vm contains a manual mac address which may contain uppercase characters.

Closes: #2509

Type of change

Please mark options that are relevant:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to
  not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the CONTRIBUTION guidelines of
  this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged

[vmwclabot]

@rconde01, you must sign our contributor license agreement before your changes are merged. Click here to sign the agreement. If you are a VMware employee, read this for further instruction.

[embano1]

Thx @rconde01 ! Would it be ok to ask for a unit/integration test, e.g. by using the simulator package?

[rconde01]

@embano1 I'll look at adding that

[vmwclabot]

@rconde01, VMware has approved your signed contributor license agreement.

[dougm]

Thanks @rconde01 , regarding the test against vcsim, you'll need #2511

With that, the test could be as simple as the diff below, or adding a new sequence of customize, power on and wait.ip

modified   govc/test/vm.bats
@@ -7,7 +7,7 @@ load test_helper
 
   id=/DC0/vm/DC0_H0_VM0
 
-  mac=00:50:56:83:3a:5d
+  mac=00:50:56:83:3A:5D
   run govc vm.customize -vm $id -mac $mac -ip 10.0.0.1 -netmask 255.255.0.0 -type Linux
   assert_success

[rconde01]

I added a test...let me know if there's anything else i need to do.

[dougm]

lgtm, thanks @rconde01 !