Consider multiple "Device Location" keys in Mac Minis
Consider multiple "Device Location" keys in Mac Minis

Mac Minis might report multiple "Device Location" keys in the output of
`diskutil info /dev/diskN`, for example:

```
   Device Identifier:        disk1
   Device Node:              /dev/disk1
   Whole:                    Yes
   Part of Whole:            disk1
   Device / Media Name:      ST2000LM003 HN-M201RAD

   Volume Name:              Not applicable (no file system)
   Mounted:                  Not applicable (no file system)
   File System:              None

   Content (IOContent):      GUID_partition_scheme
   OS Can Be Installed:      No
   Media Type:               Generic
   Protocol:                 SATA
   SMART Status:             Verified

   Disk Size:                2.0 TB (2000398934016 Bytes) (exactly 3907029168 512-Byte-Units)
   Device Block Size:        512 Bytes

   Read-Only Media:          No
   Read-Only Volume:         Not applicable (no file system)

   Device Location:          Internal
   Removable Media:          Fixed

   Solid State:              No
   Virtual:                  No
   OS 9 Drivers:             No
   Low Level Format:         Not supported
   Device Location:          "Lower"
```

Notice that the above example contains:

```
   Device Location:          Internal
```

And:

```
   Device Location:          "Lower"
```

Which then causes equality checks against the value to fail (since the
final value retrieved by `get_key` contains multiple lines).

As a solution, we modify `get_key` to accumulate all found values into a
space separated string, and we then use `=~` to check against it.

See: https://github.com/resin-io/etcher/issues/983
Signed-off-by: Juan Cruz Viotti <4148f5869aa1bcd7efd85b513a5874967e585032@openmailbox.org>

resin-io/drivelist,resin-io-modules/drivelist,resin-io/drivelist,resin-io-modules/drivelist,resin-io-modules/drivelist,resin-io-modules/drivelist