Version 1.0.1: bug fixes and minor improvements

Version 1.0.1: bug fixes and minor improvements

• Merge pull request #124 from jpbarraca/master [cf9771a]
  • Timeout support for wait_for_edge (replaces PR #62)
• Merge pull request #123 from bubbapizza/master [8b4f7f2]
  • Added a delay parameter for GPIO.setup() for udev permissions
• Merge pull request #121 from dengber/master [50e8883]
  • ADC.read() returns wrong value
• Merge pull request #64 from olegantonyan/master [d1e8dc1]
  • Wait until GPIO file appears on the /sys filesystem (issue #36)
• Merge pull request #106 from cocasema/master [12b79d7]
  • Treat warnings as errors
• Merge pull request #119 from JesseMcL/pr [e7e987a]
  • Add GPIO pullup configurations and fix PWM Segfault on kernel 4.1+
• Merge pull request #116 from kozga/master [1b04cdf]
  • Fix SPI: IOError: [Errno 22] Invalid argument in xfer and xfer2 funct…