Update pinned versions to avoid Pillow vulnerabilties

See https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst

requirements/main.txt

@@ -1,12 +1,12 @@
 # requirements.txt can be used to replicate the developer's build environment
 # setup.py lists a separate set of requirements that are looser to simplify
 # installation
-cffi == 1.14.3
-coloredlogs == 14.0  # technically optional
+cffi == 1.14.5
+coloredlogs == 15.0  # technically optional
 img2pdf == 0.4.0
 pdfminer.six == 20201018
-pikepdf == 2.0.0
+pikepdf == 2.9.0
 pluggy == 0.13.1
-Pillow == 8.0.1
-reportlab == 3.5.55
-tqdm == 4.51.0
+Pillow == 8.1.2
+reportlab == 3.5.65
+tqdm == 4.59.0

requirements/test.txt

@@ -1,7 +1,7 @@
-pytest >= 5.0.0
+pytest >= 6.0.0
 pytest-helpers-namespace >= 2019.1.8
-pytest-xdist >= 1.31.0
-pytest-cov >= 2.10.0
+pytest-xdist >= 2.2.0
+pytest-cov >= 2.11.1
 python-xmp-toolkit == 2.0.1  # requires apt-get install libexempi3
                      # or brew install exempi
 #PyMuPDF == 1.13.4    # optional

requirements/watcher.txt

@@ -1 +1 @@
-watchdog == 0.10.2
+watchdog == 1.0.2